We gave the kids scraps of fabric, modeling clay, toilet paper rolls and a bucket with scissors and glue sticks and left them alone to build. They were allowed to go outside to find any other supplies they might need to complete their homes but nothing else from inside could be used.
There was a mess to be sure. But the clean up time is SO worth the investment! And to top it off the kids were very good about cleaning up after themselves. WOW! This day was a picture for me that showed how much our kids have matured and learned in the last couple years. It will go down in history as one of my favorite co-op days.