For quite some time Rails has had the ability to read in a config file you have in your home folder named .railsrc This file contains the various flags you would otherwise pass into ‘rails new’ manually. By putting your preferred options/flags into this file, every Rails app you create will be created consistently and just the way you like it.
Now I just start a new Rails app with
rails new brilliant_app_idea
And my new app is ready to rock configured just the way I prefer.