snippet.rb

UserGuest.blueprint do
  username
  password "12345"
  password_confirmation "12345"
  role
  email
  comments
end

... and then in my blueprint.rb
require 'machinist/active_record'
require 'sham'
require 'forgery'

Sham.define do
  email { Forgery(:internet).email_address }
  username { Forgery(:internet).user_name }
  description { Forgery(:lorem_ipsum).paragraphs(2) }
end