If you've got kids you'll know that they bring home a heap of art work - particularly when they first start school. It's precious, it's special, it's blinking nuisance. We have a clean out of art work every so often.
I have a big scrap book - the sort you get for a dollar at the el-cheapo shop - not the sort you pay big money for at some fancy scrap booking shop. Anything that is super precious goes in the scrap book.
Anything that doesn't warrant a place in the scrap book is photographed. Particularly costumes. My girl has several fancy dress opportunities every year. I love designing the costumes, but the reality is - by the time she needs another "survivor of a cyclone" costume she's probably going to be 10 sizes bigger. So, I photograph them. I do allow her to keep one small article to represent the costume. Her room is decorated with Charlotte's web (the "some pig" one); a couple of magic chair wings and other bits and pieces.
I figure the photos will last a longer than the original piece, and take far less room (stored electronically) than boxes of drawings and egg carton dragons.