Did you just buy and convert a few admin themes that you now have shelved for future projects or is there some sort of workflow / tool you use to integrate these themes into your rails app ?

I just found out about install_theme (https://github.com/drnic/install_theme) which looks usefull.

Personally I've been using active_admin for simple apps, which has a pretty good theme, but there's not really much variation, if any.