Rails framework and twitter bootstrap are good for your startup project, build-in generators generate source code by its way. It is a good starting point.
But I often have to change default generted source code:
- Add encoding: utf-8 into ruby file header, for Ruby 1.9.2 encoding.
- Change scaffold view files to apply bootstrap css.
- Other things you want to override default templates.
Rails provides the mechanism to custom generator behavior.
I have already got it, and source code is on github, follow README for usage.