If you buy a commercial gluten free flour mix, check to see if it already as xanthan gum in it. If so, do not add extra.

Basic Gluten Free Flour Mix

4 cups Brown Rice Flour
1 1/2 cups Potato Starch
1 cup Tapioca Starch
Mix together and keep in cool dry place.
Always mix dry ingredients together really well before adding wet ingredients.With gluten free flours you need Xanthan Gum. Its the “glue” that keeps everything together. Each individual recipe has the amount of xanthan gum that is needed.You can buy it at the Bulk Barn or health food stores.