It's easy to create a custom template with your own setup, including element styles, customized autocompletions for Scene Intros, Scene Times, Character Extensions, etc., and even default document text.
Just create a new document and customize it the way you would like. Then, choose File > Templates > Save as Template to save the file as a new template (as a .fadein.template file instead of just a .fadein file).
You'll be given the option to automatically install the newly saved template for use with Fade In. (Otherwise, templates have to be installed under File > Templates > Manage Templates before you can use them.)
You can even set the new template, once installed, as the default template for new documents under Preferences > General.