new.rb

describe Message do
  FactoryGirl.create :account, :name => "My Account" do
    create :user
    create :project do
      build :message, :author => :user
    end
  end

  # examples
end

old.rb

describe Message do
  let!(:account) { Factory(:account, :name => "My Account") }
  let!(:user) { Factory(:user, :account => account) }
  let!(:project) { Factory(:project, :account => account) }
  let!(:message) { Factory(:message, :account => account,
                                     :project => project,
                                     :author  => user) }

  # examples
end