Canvas Art. It would be really fun to find objects in your own back yard with your kids. Just use the "artist eye". It's a great lesson on positive vs negative space. http://mypartofspace.tumblr.com/post/24327072579/spray-paint-silhouette-leave
Make your own coasters with beautiful scrapbook paper and modpodge - say hello to your Christmas gifts!
Clever use of a paint strip
Learn how to melt beads and make accessories with them..