Know that this party is going to be a festive mess! Set up your decorating station in an area that can be easily cleaned.
For a kid's party, use my icing recipe below, canned frosting, or Royal Icing made with powdered egg whites. Do not use icing with raw egg whites, as they may not be healthy for children.
Don't buy a gingerbread house that is too big. The bigger they are the harder they fall, especially if they don't have a cardboard structure underneath to support enthusiastic decorating!
Even if you are buying a gingerbread house kit, buy more candy and icing for decorating.