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.
Building a Chicken Coop - Brilliant feed bin idea. No scrapping around or wasted feed on the floor. And the feed stays dry in the rain. Building a chicken coop does not have to be tricky nor does it have to set you back a ton of scratch.