This recipe is from Colette Martin's Learning to Bake Allergy-Free.
1 c. white rice flour
1/2 c. tapioca starch
1/2 c. potato starch
Blend thoroughly. Add xanthan gum (if needed) at the time of baking, since it does not blend evenly in flour mixture.
Even easier:
Blend very well two (24 oz.) bags of White Rice Flour, one bag Tapioca Starch, and one bag Potato Starch. There is less Tapioca Starch doing it this way, but I've found the blend works great in my recipes and it's much more convenient.
