With this features my templates/spip_sheet.tmpl looks like this:
<TMPL_INCLUDE NAME="spip_head.tmpl">
<body>
<div id="pagehead">
<h1 id="top"><a name="top"></a>
<div id="head">
<div style="float:left">
<TMPL_IF NAME="HEADPICTURE">
<img src="<TMPL_VAR NAME="HEADPICTURE">" \>
</TMPL_IF>
</div>
<TMPL_VAR NAME="HEADTITLE">
<div style="clear:both;"></div>
</div>
<TMPL_VAR NAME="PAGETITLE">
</h1>
<TMPL_INCLUDE NAME="spip_nav.tmpl">
</div>
<div id="pagebody">
<TMPL_IF NAME="PICTURE">
<div id="picture">
<img src="<TMPL_VAR NAME="PICTURE">" \>
</div>
</TMPL_IF>
<TMPL_VAR NAME="PAGEBODY">
</div>
<TMPL_INCLUDE NAME="spip_feet.tmpl">
</body>
</html>