One of the first drawn animation assignments for our students is a bouncing ball flip book where students use one side of the flip book to make a bouncing ball and on the reverse side they create their own animation. Squash and stretch principles are emphasized. Below is an example of the timing and squash/stretch of the ball as we animate it.
Evaluation:
2 points -- Bouncing ball
Remaining points go toward the second animation students do on the opposite side of the flip book:
2 points -- Neatness
3 points -- Smoothness of motion
3 points -- Utilization of squash and stretch principles
10 points total.