Builder

account.rb

class Account < ActiveRecord::Base
  belongs_to :package
  has_many :users
  has_many :clients
  has_many :items
  has_many :attributes
  has_many :notes
  accepts_nested_attributes_for :users
  accepts_nested_attributes_for :clients
  accepts_nested_attributes_for :attributes
  accepts_nested_attributes_for :notes
  accepts_nested_attributes_for :items
  authenticates_many :user_sessions, :scope_cookies => true, :find_options => { :limit => 1 }
end

item.rb

class Item < ActiveRecord::Base
	has_many :attributes
	has_many :notes, :as => :noteable
	belongs_to :account
	belongs_to :client
	accepts_nested_attributes_for :attributes
	accepts_nested_attributes_for :notes
	before_save :create_service_tag
	

  def create_service_tag
    if service_tag.blank?
      self.service_tag = SecureRandom.hex(3)
    end
  end
end

items_controller.rb

class ItemsController < ApplicationController
  before_filter :require_user, :except => [:search]

  def new
    @item = current_user.account.items.build
    @item.notes.build #this line here
    3.times { @item.attributes.build }
  end
end

new.html.erb

<h1>New Item</h1>
<%= form_for @item do |f| %>
	<%= f.label :name %>
	<%= f.text_field :name %>
	
	<%= f.fields_for :attributes do |a| %>
		<%= a.label :name %>
		<%= a.text_field :name %>
		<%= a.label :value %>
		<%= a.text_field :value %>
	<% end -%>
	
	<%= f.fields_for :notes do |note| %>
		<%= note.label :note %>
		<%= note.text_field :note %>
	<% end -%>
	
	<%= f.submit "Create Item" %>
<% end -%>

note.rb

class Note < ActiveRecord::Base
  belongs_to :account
  belongs_to :noteable, :polymorphic => true
end