Making fossil imprints in clay.
Find items outside like pinecones, grass, twigs, coniferous tree needles, weeds, small pieces of bark from trees, or anything that you could use to push into your clay to make an imprint.
Mrs. Nicoll shared this recipe with me, but she said that it makes a lot, so you could divide it into 4ths.
1/2 Cup Baking Soda
1/4 Cup Corn Starch
3/8 Cups of water