Gluten Free Flour Blend

Glutenfreegirl.com uses generally, 70% whole-grain flours to 30% starches or white flours.
For 1000 grams:

Choose 700 g of any of these	Choose 300 g of any of these
amaranth brown rice  buckwheat corn millet oat quinoa sorghum sweet brown rice teff	arrowroot        cornstarch        potato starch        tapioca flour        white rice flour

Combine the flours in a big container and shake it up or use a whisk to combine them until the mix is one color.
To convert gluten recipes, use 140 g of this mixture for every 1 cup of all purpose flour.

From a FaceBook Post (I have not yet tried this.)