Since Github started forcing SSL in all its URLs, we need to download the template file separately:
wget --no-check-certificate https://github.com/dcrec1/rails4_template/raw/master/rails4_template.rb -O /tmp/rails4_template.rb
Then whenever you want to create a new project, just do:
rails new app_name -T -m /tmp/rails4_template.rb
Change app_name for your project name. You can configure what you need and run rake db:migrate to get started.