This is a quick and cute project that I came across on Art Sub Lessons (a website that I LOVE!) We've had several snow days this year, and it's always hard to come up with something that I can do with the few kids who are there.
Students could basically do whatever doodles they wanted, they just had to FILL the page. When they were finished working in Sharpie, they took styrofoam cups and traced 3 (or more) circles. Anything that fell within the circle was colored in. SO simple, and as the above website states, perfect for a supply teacher!