BUT IF YOU CUT THE STRIPS OF FABRIC (FROM WHICH YOU MAKE YOUR STARTING SQUARES) ON THE BIAS, ALL YOUR HST EDGES WILL BE ON THE STRAIGHT OR CROSS GRAIN. Don't shy away from trying this! Just let the feed dogs do all the work feeding the fabric to eliminate any distortion of fabric edges. I use this method a lot when I have to make a lot of HSTs from the same two selected fabrics.
I have seen this method referred to as the "sewn squares method."