When we first began gluten-free cooking, I remember one cookbook author suggested using garfava bean flour, and I bought it but could never quite get over the overpowering smell and taste (in uncooked foods). The good thing is that most of the bean taste disappears once you cook it. But sometimes I liked to sample my foods before popping them into the oven.
Gluten-Free White Bean Flour
My main gluten-free flour mix uses two rice flours and a small amount of white bean flour. There's actually only about a tablespoon and a half of the bean flour per cup of my mix. I chose white bean flour because it is a very mild bean flour. Price wise, it's also usually much less expensive than other bean flours. (But please keep it quiet that we're using it in gluten-free baking, or the price like anything labeled gf might soar!)
Update 11/20/13 - New - You Don't Need Bean Flour
I recently discovered that if you are using Authentic Foods brand white rice flour
and sweet rice flour
you don't need to add any bean flour to the mix. Authentic Foods gluten-free flours are very finely ground flours and starches and you do not have to add the bean flour, but even without the addition of the bean flour you're still get incredibly delicious baked goods.
So that makes my mix even easier to prepare. Simply whisk together two flours and you're ready to start baking.