If you don't put anything between the <formtemplate> and the </formtemplate> tags, the form is rendered as specified by the
style attribute of the <formtemplate> tag.
By default the standard style is used, but you can provide a customized style or adjust one of the styles provided (you will find them at /yourservice/packages/acs-templating/resources/forms
)
To customize the rendering without affecting the styles you could use the template::form::template API (for example putting the line
ns_log notice "[template::form:template myform]"
somwhere in your tcl and then cut and paste the resulting output between the <formtemplate> and the </formtemplate> tags.
You are then free to customize the rendering of the form as you please.