This is a great day to get some decorative candies for them. Halloween candies are marked down everywhere. Think about what would look good on top of the roof, around windows, etc. and pick them up now. If you find any clear hard candies marked down, they can be crushed and maked into the window openings for 'glass' windowpanes.
"Mary Janes" (a flat, toffee colored candy) make good shutters next to windows, walkways or roof shingles. Skittles are bright and colorful, and look really pretty on the gingerbread trees. Use your imagination (and your coupons, if you have any) to make a really beautiful, yet affordable gingerbread house this holiday season.