Elf house on a tree! That would be cute in the garden, especially in the tree over grown with ivy. How about some battery tea lights in the windows during outdoor parties. I hear the fairies/elves whispering "home school project" in my ear.
Buy white paper lanterns at any party store. Print out Jack Skellington pumpkin carving pattern (also pinned here). Cut out pattern. Tape or glue to lanterns. (You can also light them up with string lantern lights)