modify default gemset for new projects

I have a standard set of gems ( gems like rspec and factory_girl for
example) which in most cases always get added to a project and I was
wondering if anyone could point me in the right direction for an easy
way to customize the rails new generator to include these gems by
default in the generated gemfile.

Juan Alvarado wrote in post #1011279:

I have a standard set of gems ( gems like rspec and factory_girl for
example) which in most cases always get added to a project and I was
wondering if anyone could point me in the right direction for an easy
way to customize the rails new generator to include these gems by
default in the generated gemfile.

Look into Rails Application Templates.

I don't know how up-to-date the output is from this, but to see the
application templates in action take a look at:

http://railswizard.org

Pick a new gems and then take a look at the template the site creates.