seeding_data.rb

class Seed
  def self.start
    seed = Seed.new
    seed.generate_users
    seed.generate_items
    seed.generate_orders
  end

  def generate_users
    5.times do |i|
      User.create(name: Faker::Name.name, email: Faker::Internet.email)
      puts "Created user number #{i}"
    end
  end

  def generate_items
    10.times do |i|
      Item.create(
        name: Faker::Commerce.product_name,
        description: Faker::Lorem.paragraph,
        image_url: "http://robohash.org/#{i}.png?set=set2&bgset=bg1&size=200x200)"
    end
  end 

  def generate_orders
    10.times do |i|
      user = User.offset(rand(User.count)).first
      order = user.orders.create!
      puts "Created Order #{order.id}"
      add_items(order)
    end 
  end 

  def add_items(order)
    3.times do |i|
      item = Item.offset(rand(Item.count)).first   #offset from ActiveRecord
      order.items << item 
    end 
  end 

end

~~~~~~~~~~~~~~
Or
~~~~~~~~~~~~~~~
class Seed
  def self.start
    seed = Seed.new
    seed.generate_users
    self.generate_admins
    seed.generate_orders
  end

  def generate_users
    5.times do |i|
      User.create(name: Faker::Name.name, email: Faker::Internet.email)
      puts "Created user number #{i}"
    end
  end

  def generate_admins
    admin_credentials = [
      name: "Josh",   email: "josh@example.com"},
      name: "Tess",   email: "Tess@example.com"},
      name: "Lovisa", email: "lovisa@example.com"}
    ]
    User.create(admin_credentials)
  end 

  def generate_orders
    10.times do |i|
      order = Order.create do |order|
        order.user = User.offset(rand(User.count)).first
        order.items = [random_item, random_item, random_item]
      end 
      puts "Created Order #{order.id}"
    end
  end 

  def random_item
    Item.offset(rand(Item.count)).first
  end

end