I have had great success with this recipe and treat it just like a wheat pastry.
1/2 c tapioca flour
1 c butter
3/4 c potato starch
1 c sweet rice flour (also called glutenous rice flour)
1 heaping teaspoon xanthan gum
1/2 teaspoon salt
1 egg (cold)
4 tablespoons ice water
1 tablespoon vinegar (I use apple cider vinegar)
Mix all dry ingredients. Cut in butter until course crumbs. Add vinegar, egg and water and mix until soft ball is formed. Refrgerate until needed. (I have success freezing the dough and allowing to thaw when I need it. Enough for 2 9" pie crusts.