For a recent L. A. F. activity, kids made pumpkins and ghosts with homemade playdough. The recipe is as follows:
1 cup lukewarm/warm (not hot) water
1 cup flour
1/4 cup salt
2 teaspoons cream of tartar
1 teaspoon vegetable oil
Mix all about ingrediants thoroughly in a saucepan. This works best if you use a whisk to get rid of lumps. Then place the saucepan on the stove and cook over medium heat while stirring continuously - using a wooden spoon. (You need a wooden spoon as once the playdough starts to thicken up, if you were using a metal spoon you'd bend it!) Keep scraping the bottom and sides to keep all the dough incorporated.
The dough is ready to take off the heat when it thicken and all begins to pull into one large lump. (If you've ever cooked the dough for cream puffs it'll be similar to that.)
After the dough has cooled enough you may color it with a packet of koo-aid by kneading it in completely - beware of the color blues and purples - they tend to stain hands more easily while mixing.