Salt dough recipe: 1/2 cup salt, 1/2 cup warm water, 1 cup flour. Rolled out the dough and cut the shapes. Then poked large holes for the string, baked them at 250 for around two hours (until hard all the way through), paint with acrylic paints if desired.
I love the idea of "thumbprint" art..since I have no talent but have a thumb..and it's a kind of momento as the kids are growing, etc. This site is a great starting point for info/links for many projects besides Christmas.