While convenient, store-bought blends may not always deliver the best results, especially in more delicate baked goods. For items like biscuits, pie crusts, or cinnamon rolls, the flavor and texture can sometimes fall short of expectations. Many experienced gluten-free bakers find that store-bought blends lack the flavor profile needed for certain recipes. Most DIY blends I have found have some variation of the ingredients listed below.
300 grams White Rice Flour (fine ground) DO NOT USE SWEET WHITE RICE FLOUR, they are different things
240 grams cornstarch
160 grams tapioca starch
75 grams finely ground brown rice flour (avoid stone ground as it is grittier)
100 grams non-fat milk powder
30 grams potato starch
20 grams xanthan gum
My preferred mixing method is to pour everything into a large bowl that I have and give it a thorough whisk. I then transfer the mix into the storage container I use, which is big enough I can give everything a really good shake. This has worked well for me.
Alternatively, you could mix up smaller batches of the flour blend in a food processor or blender to ensure thorough mixing.