Eleanor Burns method makes 8 at a time and not on the bias.
Jusr draw an X on a large square and sew down each side of lines. Cut in half both ways and then on lines.
For 2 1/2 in HST use 2 six in squares. Just add 2 in for each size up. 8 in for 3 1/2 etc.
You will need to square up but with just a very small amount of waste.
Her square up ruler saves so much time because you only make one cut.