When the sun is shining and I'm feeling happy, I'll do a little something the lady calls "wiggle worm". Basically, I roll around on my back and from side to side, sort of twisting at the same time. Although it would be best to show it on a video (maybe some day), the following photos will give you an idea:
Step 1: appear as if nothing extremely exciting is about to happen.

Step 2: Suddenly, flip over and pause.

Step 3: Flip over and twist (show some claw in an attempt not to be too cute).

Repeat the flips and twists about four times.
Step 4: Rest.