1 tsp. cornstarch
1/2 tsp. water
1/2 tsp. cold cream
Food coloring
Muffin tin

In each cup of the muffin tin mix 1 teaspoon cornstarch, 1/2 teaspoon water, 1/2 teaspoon cold cream and a couple of drops of food coloring, a different color for each cup. Stir.

Now you're ready. See if you can get your grown-up assistant to sit still and let you practice.