How I typically structure my Rspec model specs.

model_spec_structure.rb

require 'spec_helper'

describe Order do
  describe '.responds_to' do
    # attributes
    it { should respond_to(:recipient_name) }
    it { should respond_to(:shipping_to_address) }
    it { should respond_to(:shipping_to_city) }
    it { should respond_to(:shipping_to_state) }
    it { should respond_to(:shipping_to_zip) }
    it { should respond_to(:phone) }
    it { should respond_to(:status) }
    it { should respond_to(:cost) }
    
    # associations
    it { should respond_to(:coupon) }
  end

  describe '.valid?' do
    # check to make sure our factory is valid
    it 'has a valid factory' do
      order = FactoryGirl.build(:order)
      order.should be_valid
    end

    # test validations with shoulda_matchers
    it { should validate_presence_of(:recipient_name) }
    it { should validate_presence_of(:shipping_to_address) }
    ...
  end

  # Now test all methods in the model. For more good info on writing specs:
  # http://blog.carbonfive.com/2010/10/21/rspec-best-practices/

  describe '.create' do
    before do
      @order = FactoryGirl.build(:order)
    end

    it 'sends a notification email to the user' ...
  end
end