The FT_View class subclasses Smarty, so if you know how to deal with Smarty templates, you will know how to deal with
templating ForwardTrack. Smarty is documented here.
Lotsa Smarty Templates...
To find your templates, look in ft/style/templates, they are all there.
The templates are named to indicate their functions, but for specific detail you can poke
around in ft/dispatch.php and the ft/lib/FT/App.class.php and ft/lib/FT/App/*App.class.php files.
It is now possible to further customize the look and feel of ForwardTrack campaigns. However, customization beyond what is available through this administrative interface requires a more technically-driven approach -- you will have to copy/create/edit HTML template files, and upload them to the correct location on the FT server.
The steps to do this are listed in the 'Documentation' section of the Administrative interface of a functioning ForwardTrack installation, so look there.