Lydia's preschool uses homeade play dough that is really fantastic. It lasts a long time and has a great texture. I asked the lady that makes it for the recipe, and she said she just uses a "regular" play dough recipe, but instead of vegetable oil, she uses baby oil. I used a basic play dough recipe and exchanged the oils, and the play dough is great! It is still smooth and pliable a month after we made it, and it has a nice texture. Here is the recipe I use:
1 c all-purpose flour
1/2 c table salt
2 T cream of tartar
1 T baby oil
1 c water
Mix all of these together in a small saucepan. Cook, stirring, over medium heat until it forms a big lump. Dump it onto a cutting board (or table, or whatever) and knead it a few times. It will feel sticky at first, but it gets better. Then, add coloring:
We make a well in the middle and add a few drops of desired food coloring. Close the well with more dough and knead (this way you don't stain your hands). We split one batch of playdough into two, so we get two colors from each batch. Each batch makes 2 baseball-sized balls of dough.
Malachi really likes making the colors. He mixed most of ours.
Today, we made 2 batches, to add to the 2 batches we made about a month ago, so now we have 8 colors: white (uncolored), green, blue, orange, yellow, red (or dark pink), light purple, dark purple, and a blue/green. You can also add glitter and knead it in the same way as the colors. My kids love to play with play dough with small plastic animals as well as the usual cookie cutters and rolling pins. Small cars are good, too, for making tracks.
Note: I used a stainless steel pan to cook it in, and afterwards it looks like it would be hard to clean up, but I just add some water and it washes right up easily.