Because the end of one section is the beginning of another, you can sort-of automate the vignettes by defining the section as beginning with the vignette if the section is section 2 or greater,
\ifnum\value{section}<2\else\nicesectionending\fi
which leaves the final ornament, which could be done manually, or with an empty section \section*{}.

One way to redefine the section format is with titlesec.
\usepackage{titlesec}
\titleformat{\section}[display] {\normalfont\ifnum\value{section}<2\else\nicesectionending\vskip3em\fi\large\bfseries}{\S \thesection}{0pt}{}
MWE
\documentclass[12pt]{article}
\usepackage{lipsum}
\usepackage{fourier}%adforn}
\newcommand*\myhrulefill{%
\leavevmode\leaders\hrule depth-2pt height 2.4pt\hfill\kern0pt}
\newcommand\niceending[1]{%
\begin{center}%
\LARGE \myhrulefill \hspace{0.2cm} #1 \hspace{0.2cm} \myhrulefill%
\end{center}}
\newcommand*\nicesectionending{\niceending{\aldineright\aldineleft}}
\newcommand*\nicesubsectionending{\niceending{\aldinesmall}}
\usepackage{titlesec}
\titleformat{\section}[display] {\normalfont\ifnum\value{section}<2\else\nicesectionending\vskip3em\fi\large\bfseries}{\S \thesection}{0pt}{}
\newcommand\sampletext{Etiam euismod. Fusce facilisis lacinia dui. Suspendisse potenti. In mi erat, cursus
id, nonummy sed, ullamcorper eget, sapien. Praesent pretium, magna in
eleifend egestas, pede pede pretium lorem, quis consectetuer tortor sapien facilisis
magna. Mauris quis magna varius nulla scelerisque imperdiet.}%from lipsum[12]
\begin{document}
\section{First Example}
\sampletext
\section{Second Example}
\sampletext
\section{Third Test}
\sampletext
\section{Test}
\sampletext
\section{Test}
\sampletext
\section*{}
%\nicesectionending
\end{document}
begin{mysection}...\end{mysection}is possible. But I think it will be more typing in the end. – yannisl Mar 02 '11 at 21:24\end{Section}). It's probably less typing to define something like\newcommand*\obreak{\medskip\hrulefill\quad\floweroneleft\floweroneright\quad\hrulefill\medskip}(to use Yiannis's answer from his link) and then just use\obreakwhere you want it. – TH. Mar 02 '11 at 23:00