I find that buying pre-made all purpose gluten free flour is very expensive at the store per pound so I basically make my own.
Also, living at an altitude of 4,750 elevation requires a little more protein in my mix to help with that sponginess you would get from all Wheat Flours.
When I make my flour blend I love using Teff Flour as one of my blends. It is high in protein — which most GF Flours lack.
I also prefer using Bob’s Red Mill brand and tend to go with that brand when making my blend.