\documentclass[tikz,border=2mm]{standalone}
\usetikzlibrary{arrows.meta}

\begin{document}
\begin{tikzpicture}
\foreach \arrowtipkind[count=\i from 0] in {
Circle,
Diamond,
Ellipse,
Kite,
Latex,
Rectangle,
Square,
Stealth,
Triangle,
Turned Square,
Arc Barb,
Bracket,
Hooks,
Tee Barb,
Parenthesis,
Implies,
Butt Cap,
Fast Round,
Fast Triangle,
Round Cap,
Triangle Cap}{\foreach \specs[count=\j from 0] in {round, open, fill=red, {round, fill=blue, length=2.5mm, slant=.5}}{\draw[-{\arrowtipkind[\specs]}, yshift=-1.5*\i cm -0.2*\j cm] (0,0) -- +(1,0)\ifnum\j=0 node[above,midway,font=\scriptsize\ttfamily]{\arrowtipkind}\fi;};};
%%% Tips with particular options:
% Arc Barb[sep, arc=, length=, line width=, width=, reversed, round, slant=, harpoon, left, right, ]
% Bracket[sep, reversed, round, slant=, left, right, harpoon, reversed, ]
% Hooks[sep, arc=, length=, line width=, width=, reversed, round, slant=, harpoon, left, right, ]
% Tee Barb[sep, inset=, inset'= , line width=, reversed, round, slant=, harpoon, left, right, ] thin thick
% Implies[]
\end{tikzpicture}
\end{document}

\documentclass{standalone}

\usepackage{tikz}
\usetikzlibrary{intersections}

\begin{document}
\begin{tikzpicture}
    % Draw to path and give a name to them
    \draw [red, name path={red line}] (0,0) -- (4,3);
    \draw [blue, name path={blue curve}] (1,-0.5) to[out=80, in=100] (3,2);
    % use the intersections on a path to giv them coordinates
    % and draw a line between them
    \draw [green, name intersections={of=red line and blue curve, 
           by={first intersect, second intersect}}]
       (first intersect) -- (second intersect);
    % one can use the coordinates furtheron
    \node [above] at (first intersect) {A};
    \node [below] at (second intersect) {B};
\end{tikzpicture}
\end{document}

\documentclass{standalone}% or wathever you want

% load packages
\usepackage{tikz, xcolor}
% load libraries
\usetikzlibrary{intersections,shapes.arrows,calc}

% define light and dark gray
\definecolor{lgray}{cmyk}{0,0,0,0.2}
\definecolor{dgray}{cmyk}{0,0,0,0.7}

% make some settings
\tikzset{%
    % style for the intersecting path, which
    % are nessesary for the calculation but
    % shouldn't be drawn in the final image
    ipath/.style={
%       draw,% comment this aout after construction
        red
    },
    % style for an arrow used as object
    optical arrow/.style={%
        fill=dgray,
        inner sep=3pt,
        shape=single arrow,
        minimum width=0.5cm,
        minimum height=1.5cm,
        outer sep=0pt,
        shape border rotate=90,
    },
    % style for the virtual image
    virtual optical arrow/.style={%
        fill=lgray,
        inner sep=3pt,
        shape=single arrow,
        minimum width=0.5cm,
        minimum height=1.5cm,
        outer sep=0pt,
        shape border rotate=90,
    },
    % style for the mirror
    mirror/.style={%
        line width=2pt,
    },
    % style for the axis
    optical axis/.style={%
        thin,
    },
    % style for light rays
    ray/.style={%
        thin,
        ->,
    },
    % style for imagined rays, which ar not real
    % but help by constructin the image
    imagined ray/.style={%
        ray, dgray, -,
    },
    % alias
    virtual ray/.style={imagined ray},
    % style for (focal) points
    point/.style={%
        fill=black,
        radius=0.8pt,
        inner sep=1pt,
        shape=circle,
        minimum size=2pt,
        outer sep=2pt
    },
}

% set three layers
\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}
% and define shortcuts to access them
\newcommand{\bglayer}[1]{%
    \begin{pgfonlayer}{background}%
    #1%
    \end{pgfonlayer}%
}
\newcommand{\fglayer}[1]{%
    \begin{pgfonlayer}{foreground}%
    #1%
    \end{pgfonlayer}%
}

\begin{document}
\begin{tikzpicture}
    % define the bounding box is nessesarx because the ipaths
    % make it bigger than needed
    \path [use as bounding box] (-5.2,-5) rectangle (6.2,5);
    % define variables, you may vary them a little
    %% radius
    \def\radius{5}
    \def\radiusII{5.05}
    %% focal distancs = \radius/2
    \def\focal{2.5}
    %% object size
    \def\size{1.cm}
    %% object width
    \def\owidth{1.25}
    % draw mirror
    %% the extra ipath is nessesary to get nicer rays
    \path [ipath, name path=M] (\radius,0) ++(90:\radius)
          arc (90:270:\radius);
    \fglayer{%
        \draw [mirror] (\radiusII-0.05,0) ++(130:\radiusII)
              arc (130:240:\radiusII);
    }
    % draw focal point
    \node (B) at (\focal,0) [point] {};
    % draw object
    \node (O) [optical arrow,anchor=tail, minimum height=\size] %
          at (\owidth,0) {};
    %% description
    \node [above right] at (O.tip) {object};
    % rays
    %% draw axis ray
    \draw [ray] (O.tip) -- (0,0) -- ($(0,0)!3!(\owidth,-\size)$);
    %% draw parallel ray
    \path [ipath, name path=PS] (O.tip) -- ++(-3,0);
    \draw [ray, name intersections={of=M and PS, by=M-PS}]
        (O.tip) -- (M-PS) -- ($(M-PS)!2!(B)$);
    %% caculate virtual axis ray
    \path [ipath, name path=AS-V] ($(0,0)!-4!(\owidth,-\size)$) -- (0,0);
    %% calculate virtual parallel ray
    \path [ipath, name path=PS-V] ($(M-PS)!-4!(B)$) -- (M-PS);
    %% draw virtual axis ray
    \draw [imagined ray, name intersections={of=AS-V and PS-V, by=Tip-V}]
        (Tip-V) -- (0,0);
    %% draw virtual axis ray
    \draw [imagined ray] (Tip-V) -- (M-PS);
    % draw virtual object
    \bglayer{\path let \p{1}=(Tip-V) in 
        (Tip-V) node (V) [minimum height=\size,
                          scale={\y{1}/\size*0.665},
                          virtual optical arrow,anchor=tip
                         ] {};}
    %% description
    \path (V.west) node [left] {virtual image};
    % draw optical axis
    \fglayer{\draw [optical axis] (-5,0) --++(11,0);}
\end{tikzpicture}
\end{document}

\documentclass{standalone}

\usepackage{tikz}
\usetikzlibrary{calc}

\begin{document}
\begin{tikzpicture}
    % make some mathematical calculations
    \node (a) at (1,1) {A};
    \fill [red] ($(a) + 1/3*(1cm,0)$) circle (2pt);
    % draw a segment of a path between two points
    \coordinate (b) at (0,0);
    \coordinate (c) at (0.5,3);
    \fill (b) circle (1pt) (c) circle (1pt);
    \draw [blue!50!green, ->] (b) -- ($(b)!1.5!(c)$);
    \draw [blue, ->] (b) -- ($(b)!0.5!(c)$);
    % draw a parallel line
    \draw [green] (2,0) coordinate (d) -- (3,4) coordinate (e);
    \draw [green, dashed] (2.5,1) -- ++($(e)-(d)$);
\end{tikzpicture}
\end{document}

\documentclass{standalone}

\usepackage{tikz, xcolor}
\usetikzlibrary{folding,calendar}
\begin{document}
\sffamily\scriptsize
\begin{tikzpicture}[transform shape]
\tikzstyle{every calendar}=
[
    %Formats calendars and sets positions
    at={(-8ex,4ex)},
    week list,
    month label above centered,
    month text=\bfseries\textcolor{red}{\%mt} \%y0,
    if={(Sunday) [black!50]}
    ]
\tikzfoldingdodecahedron
[
    %Sets size of calendar
    folding line length=2.5cm,
    %Adds calendar image to each face
    face 1={ \calendar [dates=\the\year-01-01 to \the\year-01-last];},
    face 2={ \calendar [dates=\the\year-02-01 to \the\year-02-last];},
    face 3={ \calendar [dates=\the\year-03-01 to \the\year-03-last];},
    face 4={ \calendar [dates=\the\year-04-01 to \the\year-04-last];},
    face 5={ \calendar [dates=\the\year-05-01 to \the\year-05-last];},
    face 6={ \calendar [dates=\the\year-06-01 to \the\year-06-last];},
    face 7={ \calendar [dates=\the\year-07-01 to \the\year-07-last];},
    face 8={ \calendar [dates=\the\year-08-01 to \the\year-08-last];},
    face 9={ \calendar [dates=\the\year-09-01 to \the\year-09-last];},
    face 10={\calendar [dates=\the\year-10-01 to \the\year-10-last];},
    face 11={\calendar [dates=\the\year-11-01 to \the\year-11-last];},
    face 12={\calendar [dates=\the\year-12-01 to \the\year-12-last];},
];
\end{tikzpicture}
\end{document}

\documentclass{standalone}

\usepackage{tikz, xcolor}
\usetikzlibrary{shapes,arrows}

\tikzstyle{decision} = [diamond, draw, text width=4.5em, 
                        text badly centered, node distance=2cm, 
                        inner sep=0pt]
\tikzstyle{block} = [rectangle, draw, text width=5em, 
                     text centered, rounded corners, 
                     minimum height=4em, node distance=3cm]
\tikzstyle{line} = [draw, -latex']
\tikzstyle{cloud} = [draw, ellipse, node distance=2.5cm, minimum height=2em]
\tikzstyle{blank} = [node distance=1cm]

\begin{document}
\begin{tikzpicture}[node distance = 3cm, auto]
    % Place nodes
    \node [cloud] (init) {n};    
    \node [blank, below of=init] (sup) {};
    \node [decision, below of=sup] (square) {$n^2 \le 1$};
    \node [cloud, right of=square] (end) {End};
    \node [block, left of=square] (newN) {$n = \frac{2}{n}$};

    % Draw edges
    \path [line] (init) -- (square);
    \path [line] (square) -- node [near start] {yes} (end);
    \path [line] (square) -- node [near start] {no} (newN);
    \path [line] (newN) |- (sup);
\end{tikzpicture}
\end{document}

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{mindmap,backgrounds}

\begin{document}
\tikzstyle{root concept}+=[concept color=blue!20,minimum size=2cm]
\tikzstyle{level 1 concept}+=[sibling angle=45]

\begin{tikzpicture}[mindmap]
\node [concept] (n1) {Stack Exchange Sites}
    child[concept color=red,grow=45] {node[concept] (c1) {Meta}}
    child[concept color=orange,grow=0] {node[concept] (c2) {Q \& A}}
    child[concept color=green,grow=-45] {node[concept] (c3) {Chat}};
\begin{pgfonlayer}{background}
\draw [concept connection] (c1) edge (c2)
                                edge (c3)
                           (c2) edge (c3);
\end{pgfonlayer}

\node [extra concept] at (0,10) (n2) {\TeX {} and \LaTeX {}Stack Exchange}
    child[concept color=red,grow=45] {node[concept] (s1) {Meta}}
    child[concept color=orange,grow=0] {node[concept] (s2) {Q \& A}}
    child[concept color=green,grow=-45] {node[concept] (s3) {Chat}};

\begin{pgfonlayer}{background}
    \draw [concept connection] (s1) edge (s2)
                                    edge (s3)
                               (s2) edge (s3)
                               (n1) edge (n2);
\end{pgfonlayer}
\end{tikzpicture}

\end{document}

\documentclass{standalone}

\usepackage{tikz}
\usetikzlibrary{shapes,% for the rectangle
                chains,% provides the chains
                scopes}% allows to replace \begin{scope} \end{scope} with {}

\begin{document}
\begin{tikzpicture}[
  nonterminal/.style={
    rectangle, 
    minimum size=6mm, 
    very thick, 
    draw=red!50!black!50, 
    top color=white, % a shading that is white at the top...
    bottom color=red!50!black!20, % and something else at the bottom
    font=\itshape
  },
  terminal/.style={
    rectangle,minimum size=6mm,rounded corners=3mm,
    very thick,draw=black!50,
    top color=white,bottom color=black!20,
    font=\ttfamily
  },
  node distance=5mm, every on chain/.style={join}, every join/.style={->}
]
{ [start chain]
  \node [on chain,nonterminal] {unsigned integer};
  \node [on chain,terminal] {.};
  \node [on chain,terminal] {digit};
  \node [on chain,terminal] {E};
  { [start branch=plus]
    \node (plus) [terminal,on chain=going above right] {+};
  }
  { [start branch=minus]
    \node (minus) [terminal,on chain=going below right] {-};
  }
  \node [on chain, nonterminal, join=with chain/plus-end, join=with chain/minus-end] {unsigned integer};
}
\end{tikzpicture}
\end{document}

\documentclass{standalone}

\usepackage{tikz}
\usetikzlibrary{shapes,% for the rectangle
                chains,% provides the chains
                scopes}% allows to replace \begin{scope} \end{scope} with {}

\begin{document}
\begin{tikzpicture}[
  nonterminal/.style={
    rectangle, 
    minimum size=6mm, 
    very thick, 
    draw=red!50!black!50, 
    top color=white, % a shading that is white at the top...
    bottom color=red!50!black!20, % and something else at the bottom
    font=\itshape
  },
  terminal/.style={
    rectangle,minimum size=6mm,rounded corners=3mm,
    very thick,draw=black!50,
    top color=white,bottom color=black!20,
    font=\ttfamily
  },
  every on chain/.style={join}, every join/.style={->}
]

\matrix[column sep=4mm] {
  % First row:
  & & & & \node (plus) [terminal] {+};&\\
  % Second row:
  \node (ui1)   [nonterminal] {unsigned integer};&
  \node (dot)   [terminal]    {.};               &
  \node (digit) [terminal]    {digit};           &
  \node (e)     [terminal]    {E};               &
  & % space in between
  \node (ui2) [nonterminal] {unsigned integer};\\
  % Third row:
  & & & & \node (minus)[terminal] {-};&\\
  };

{ [start chain]
  \chainin (ui1);
  \chainin (dot);
  \chainin (digit);
  \chainin (e);
  { [start branch=plus]
    \chainin (plus);
  }
  { [start branch=minus]
    \chainin (minus);
  }
  \chainin (ui2) [join=with chain/plus-end, join=with chain/minus-end];
}
\end{tikzpicture}
\end{document}

\documentclass{standalone}

\usepackage{tikz}
\usetikzlibrary{shapes,% for the rectangle
                chains,% provides the chains
                scopes}% allows to replace \begin{scope} \end{scope} with {}

\makeatletter
\def\tikz@lib@parse@join#1{%
  \def\tikz@temp{#1}%
  \ifx\tikz@temp\pgfutil@empty%
    \tikz@lib@parse@join@by by \pgf@stop%
  \else%
    \pgfutil@in@{with }{#1}% 
    \ifpgfutil@in@% 'with [by] [label]'
      \pgfutil@in@{by }{#1}%
      \ifpgfutil@in@% 'with by [label]'
        \pgfutil@in@{label }{#1}%
        \ifpgfutil@in@% 'with by label'
          \tikz@lib@parse@join@with@by@label#1\pgf@stop%
        \else% 'with by'
          \tikz@lib@parse@join@with@by#1\pgf@stop%
        \fi%
      \else% 'with [label]'
        \pgfutil@in@{label }{#1}%
        \ifpgfutil@in@% 'with label'
          \tikz@lib@parse@join@with@label#1\pgf@stop%
        \else% with
          \tikz@lib@parse@join@with@by#1 by \pgf@stop%
        \fi%
      \fi%
    \else% '[by] [label]'
      \pgfutil@in@{by }{#1}%
      \ifpgfutil@in@% 'by [label]'
        \pgfutil@in@{label }{#1}%
        \ifpgfutil@in@% 'by label'
          \tikz@lib@parse@join@by@label#1\pgf@stop%
        \else% 'by'
          \tikz@lib@parse@join@by#1\pgf@stop%
        \fi%
      \else% '[label]'
        \pgfutil@in@{label }{#1}%
        \ifpgfutil@in@% 'label'
          \tikz@lib@parse@join@label#1\pgf@stop%
        \else%
          \tikz@lib@parse@join@by#1 by \pgf@stop%
        \fi%
      \fi%
    \fi%
  \fi%
}
\def\tikz@lib@parse@join@with@by@label with #1 by #2 label #3\pgf@stop{%
  \tikzset{after node path={(#1)edge[every join,#2]#3(\tikzchaincurrent)}}%
}
\def\tikz@lib@parse@join@with@label with #1 label #2\pgf@stop{%
  \tikzset{after node path={(#1)edge[every join]#2(\tikzchaincurrent)}}%
}
\def\tikz@lib@parse@join@by@label by #1 label #2\pgf@stop{%
  \tikzset{after node path={\ifx\tikzchainprevious\pgfutil@empty\else(\tikzchainprevious)edge[every join,#1]#2(\tikzchaincurrent)\fi}}%
}
\def\tikz@lib@parse@join@label label #1\pgf@stop{%
  \tikzset{after node path={\ifx\tikzchainprevious\pgfutil@empty\else(\tikzchainprevious)edge[every join]#1(\tikzchaincurrent)\fi}}%
}
\makeatother

\begin{document}
\begin{tikzpicture}[
  nonterminal/.style={
    rectangle, 
    minimum size=6mm, 
    very thick, 
    draw=red!50!black!50, 
    top color=white, % a shading that is white at the top...
    bottom color=red!50!black!20, % and something else at the bottom
    font=\itshape
  },
  terminal/.style={
    rectangle,minimum size=6mm,rounded corners=3mm,
    very thick,draw=black!50,
    top color=white,bottom color=black!20,
    font=\ttfamily
  },
  every on chain/.style={join}, every join/.style={->}
]

\matrix[column sep=4mm] {
  % First row:
  & & & & \node (plus) [terminal] {+};&\\
  % Second row:
  \node (ui1)   [nonterminal] {unsigned integer};&
  \node (dot)   [terminal]    {.};               &
  \node (digit) [terminal]    {digit};           &
  \node (e)     [terminal]    {E};               &
  & % space in between
  \node (ui2) [nonterminal] {unsigned integer};\\
  % Third row:
  & & & & \node (minus)[terminal] {-};&\\
  };

{ [start chain]
  \chainin (ui1);
  \chainin (dot);
  \chainin (digit);
  \chainin (e);
  { [start branch=plus]
    \chainin (plus) [join=label {node[above left]{a label}}];
  }
  { [start branch=minus]
    \chainin (minus);
  }
  \chainin (ui2) [join=with chain/plus-end label {node[above right] {plus label}}, join=with chain/minus-end by dashed label {node [below right]{minus label}}];
}
\end{tikzpicture}
\end{document}

\documentclass[parskip]{scrartcl}
\usepackage[margin=5mm,a3paper]{geometry}
\usepackage{kerkis}
\usepackage{tikz}
\usetikzlibrary{
    shapes,
    shapes.geometric,
    shapes.symbols,
    shapes.arrows,
    shapes.multipart,
    shapes.callouts,
    shapes.misc}

\begin{document}

\tikzset{every node/.style={draw=red!20!black,fill=orange!50!red!50!white,text=black,inner sep=2pt}}

{\LARGE \textbf{Standard shapes}}\\
\foreach \shape in {circle,rectangle}
{   \begin{tikzpicture}
        \node[shape=\shape] {\shape};
    \end{tikzpicture}
}
\\\hrule

{\LARGE \textbf{Geometric shapes}}\\
\foreach \shape in {diamond,ellipse,trapezium,semicircle,regular polygon,star,isosceles triangle,kite,dart,circular sector,cylinder}
{   \begin{tikzpicture}
        \node[shape=\shape] {\shape};
    \end{tikzpicture}
}
\\\hrule

{\LARGE \textbf{Symbol shapes}}\\
\foreach \shape in {forbidden sign,magnifying glass,cloud,starburst,signal,tape}
{   \begin{tikzpicture}
        \node[shape=\shape] {\shape};
    \end{tikzpicture}
}
\\\hrule

{\LARGE \textbf{Arrow shapes}}\\
\foreach \shape in {single arrow,double arrow,arrow box}
{   \begin{tikzpicture}
        \node[shape=\shape] {\shape};
    \end{tikzpicture}
}
\\\hrule

{\LARGE \textbf{Multipart shapes}}\\
\foreach \shape in {circle split,circle solidus,ellipse split,rectangle split}
{   \begin{tikzpicture}
        \node[shape=\shape] {\shape};
    \end{tikzpicture}
}
\\\hrule

{\LARGE \textbf{Callout shapes}}\\
\foreach \shape in {ellipse callout,rectangle callout,cloud callout}
{   \begin{tikzpicture}
        \node[shape=\shape] {\shape};
    \end{tikzpicture}
}
\\\hrule

{\LARGE \textbf{Miscellaneous shapes}}\\
\foreach \shape in {cross out,strike out,rounded rectangle,chamfered rectangle}
{   \begin{tikzpicture}
        \node[shape=\shape] {\shape};
    \end{tikzpicture}
}

\end{document}

\documentclass[tikz,margin=1]{standalone}
\usetikzlibrary{decorations.pathmorphing}
\def\y{0}
\newcommand\decorated[1]{
    \tikzset{decoration=#1}
    \draw[thin,red] (0,\y) to[bend left] (1,\y);
    \filldraw[decorate,fill=yellow!60,very thick] (0,\y) to[bend left] (1,\y)
        node[right,font=\ttfamily] {#1};
    \let\auxy\y
    \pgfmathsetmacro\y{\auxy+1}
}
\begin{document}
\begin{tikzpicture}[y=-1cm,x=3cm]
\decorated{lineto}
\decorated{straight zigzag}
\decorated{random steps}
\decorated{saw}
\decorated{zigzag}
% We are not able to use our command here :(
\tikzset{decoration=bent}
\draw[thin,red] (0,\y) -- (1,\y);
\filldraw[decorate,fill=yellow!60,very thick] (0,\y) -- (1,\y)
    node[right,font=\ttfamily] {bent};
\let\auxy\y
\pgfmathsetmacro\y{\auxy+1}
% %
\decorated{bumps}
\decorated{coil}
\decorated{curveto}
\decorated{snake}
\end{tikzpicture}
\end{document}

\documentclass[tikz,margin=1]{standalone}
\usetikzlibrary{decorations.markings}
\begin{document}
\colorlet{darkgreen}{green!70!black}
\begin{tikzpicture}[>=stealth]
\path (0,1) node[right,inner sep=0pt,font=\ttfamily] {markings};
\draw[postaction=decorate,decoration={
        markings,
        mark=at position 0.5 with \arrow{>}
      }] (0,0) -- (3,0) node[right=1ex] {One marking only};
\draw[postaction=decorate,decoration={
        markings,
        mark=at position 1/3 with {
          \draw[red,thick] (-2pt,-2pt) -- (2pt,2pt);
          \draw[red,thick] (-2pt,2pt) -- (2pt,-2pt);
        },
        mark=at position 2/3 with {
          \draw[darkgreen,thick] (-2pt,0) -- (0,-2pt) -- (2pt,2pt);
        }
      }] (0,-1) -- (3,-1) node[right=1ex] {Two markings};
\draw[postaction=decorate,decoration={
        markings,
        mark=between positions 0 and 1 step 0.2 with {
          \filldraw[fill=yellow] 
            (-3pt,-3pt) -- (3pt,-3pt) -- (0,3pt) -- cycle;
          \draw (0,2pt) -- (0,-1pt);
          \fill (0,-2pt) circle (.5pt);
        }
      }] (0,-2) to[bend left] (3,-2) node[right=1ex] {Several markings};
\end{tikzpicture}
\end{document}

\documentclass[tikz,margin=1]{standalone}
\usetikzlibrary{decorations.footprints}
\begin{document}
\begin{tikzpicture}[y=-1.5cm,x=3cm]
\path (0,0) node[right,inner sep=0pt,font=\ttfamily] {footprints};
\foreach \i [count=\j] in {gnome,human,bird,felis silvestris} {
    \tikzset{decoration={footprints,foot of=\i}}
    \draw[thin,red] (0,\j) to[bend left] (1,\j);
    \draw[decorate] (0,\j) to[bend left] (1,\j) node[right] {\i};
}
\end{tikzpicture}
\end{document}

\documentclass[tikz,margin=1]{standalone}
\usetikzlibrary{decorations.shapes}
\def\y{0}
\newcommand\decorated[1]{
    \tikzset{decoration=#1}
    \draw[thin,red] (0,\y) to[bend left] (1,\y);
    \draw[decorate] (0,\y) to[bend left] (1,\y)
        node[right,font=\ttfamily] {#1};
    \let\auxy\y
    \pgfmathsetmacro\y{\auxy+1}
}
\begin{document}
\begin{tikzpicture}[y=-1cm,x=3cm]
\decorated{crosses}
\decorated{triangles}
\decorated{shape backgrounds} % You can customize it. See more in the manual
\end{tikzpicture}
\end{document}

\documentclass[tikz,margin=2]{standalone}
\usetikzlibrary{decorations.text}
\begin{document}
\begin{tikzpicture}[y=-1cm,x=3cm]
\draw[postaction=decorate,decoration=text along path,
      /pgf/decoration/text={Hello world}] 
    (0,0) to[bend left] (1,0) node[right=1ex,font=\ttfamily] {text along path};
% Source: The TikZ - PGF manual, version 3.1.3, 9 May 2019, page 652
\tikzset{
    decoration={
        text effects along path,
        text={Hello world}, 
        text align=center,
        text effects/.cd,
            character count=\i,
            characters={xslant=0.5, text along path, name=c-\i}
    }
}
\draw[postaction=decorate] (0,1) -- (1,3.5) 
    node[right=1ex,font=\ttfamily] {text effects along path};
\end{tikzpicture}
\end{document}

\documentclass[tikz,margin=1]{standalone}
\usetikzlibrary{decorations.fractals}
\def\y{0}
\newcommand\decorated[3][]{
    \tikzset{decoration=#2}
    \draw[ultra thin,red] (0,\y) -- (1,\y);
    \draw[#1] decorate {
                decorate { 
                  decorate { 
                    (0,\y) -- (1,\y)
                  }
                }
              };
    \path (1,\y) node[right=1ex,font=\ttfamily] {#2};
    \let\auxy\y
    \pgfmathsetmacro\y{\auxy+#3}
}
\begin{document}
\begin{tikzpicture}[y=-1cm,x=3cm]
\decorated{Koch curve type 1}{1.5}
\decorated{Koch curve type 2}{2}
\decorated{Koch snowflake}{1}
\decorated[ultra thick]{Cantor set}{0}
\end{tikzpicture}
\end{document}