Making gingerbread houses is a riot for kids, especially when there’s plenty of candy to choose from. Some candy ideas:
M&Ms
Gum drops
Marshmallows
Candy canes
Peppermint and spearmint candies (the round ones)
Sour punch straws
Licorice (especially Twizzlers pull-aparts for thin strings)
Chex (for shingles)
Smarties
Gummy Christmas trees
Skittles
Red Hots
Shredded coconut (for snow)
Pretzel sticks and squares
Ice cream cones (to use and decorate as trees)
Lollipops
Buttermints
Silver balls
You can simply use royal icing and graham crackers for your house bases. Or, you can make gingerbread of your own. This article from AllRecipes includes thorough instructions for making, cutting, and assembling your own gingerbread houses.
Here are a couple other top-rated recipes for gingerbread usable for houses:
Food Network Gingerbread House
Next, you'll need templates for gingerbread houses:
Traditional, with front door and window cutouts
20 free templates (including church and mini house patterns)
For grown ups or more intense gingerbread house makers, Sweetopia has some great ideas for creating snowmen, Christmas trees (ice cream cones with icing piped on), and more.
Photo from Sweetopia
When the decorating is done, select three judges to vote on the top houses. The winner gets to eat some of the remaining candy and is exempt from cleaning up.