pgfplots-examples/scheme.tex

\documentclass[border=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes,shadows,arrows}

\tikzstyle{startnode} = [rectangle, rounded corners, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=gray!50]

\tikzstyle{corenode} = [rectangle, rounded corners, minimum width=3cm, minimum
height=1cm, text centered, draw=black, fill=gray!10]

\tikzstyle{endnode} = [diamond, rounded corners, minimum height=1cm, text centered, draw=black, fill=red!30]

\tikzstyle{endnode2} = [diamond, text centered, draw=black, fill=red!30]

\begin{document}
\begin{tikzpicture}[node distance=2cm]

%create all of the nodes
\node (start) [startnode] {Start};
\node (step1) [corenode, below of=start] {Step 1};
\node (in) [corenode, right of=start, node distance=5cm] {In};
\node (end)[endnode2, below of =step1]{End};	
\node (out) [below of=end, node distance=2cm] {out};


\draw[->] (start) -- (step1);
\draw[->] (step1) -- (end);
\draw[->] (in) |- (step1);
\draw [->] (end) -- (out);
\end{tikzpicture}
\end{document}