It's costume season again, and face paint is a fun addition to any Halloween disguise. But rather than head to the costume store for supplies, concoct your own at home. It's easy enough that kids can help, and you save money by using everyday ingredients, such as flour, cornstarch, and vegetable oil, and mixing only the colors and amounts needed. DIY face paints are less toxic and chemical-laden than store-bought versions; some are even edible. Use an egg carton, ice cube tray, or baby food containers to keep colors separate.