Carla Sonheim's Art of Silliness class. I recommend this class, it's very fun. The worksheets she sends you each day are very unique drawing activities. What I am doing with these is photocopying them for kids in my class to work on when they are finished with their regular art projects. (She allows photocopying for classroom use in schools, which is awesome!) Some of the kids did a drawing exercise on Friday in class where they draw stacks of turtles. One stack with their left hand, one stack with their right hand. Great exercise for the brain and hand/eye coordination. The kids lOVED it. They also had a blast coming up with Fleep (nonsense) words. I also have Carla's book, which is also chock-full of fun drawing activities.