Here is the playdough recipe I use, given to me long ago by Vicki. It's easy, it's fun, and if little tummies happen to ingest a bit, it's not the end of the world. (Although still better for them not to.)

1 c. flour (I've been using up my old bleached white all-purpose flour for this)
1 c. water
1/4 c. salt (I've also been using up my old refined table salt for this)
2 tbsp. oil (good way to get rid of junky vegetable oils--that and using them to clean adhesive off off things)
2 tbsp. cream of tartar
1 pkg. Kool-Aid (the ONLY use I recommend for Kool-Aid!) in colour of choice

Mix in pot. Stir over a medium heat to make a ball. Store in the refrigerator.

I've had a couple of batches in the fridge for three years now that are still good.

Have lots of squishy fun!