Need to be rice free?  Try equal amounts sorghum or bean flour blends for rice flour in the recipe.  Need to be corn-free or potato-free?  Use equal amounts of tapioca starch, arrowroot starch, or mung bean starch to substitute for the flour that needs to be avoided in your recipes or flour recipe blends.  Select flours not already used in the recipe (e.g. for Bette Hagman’s original flour blend, use cornstarch or arrowroot or mung bean starch, not tapioca starch).  Small changes in liquids may need to be made to the recipe to account for the different flour.