To make a lot of HST's the very best method...both most speedy and most accurate....is to use the Triangulations program from Bearpaw Productions. You print out HST sheets on your home computer, sew on the dotted lines, cut apart on the solid lines and voila! a whole bunch of accurate half square triangles in no time at all, no ruler necessary.
I love, love this program and have used it for years. And you can get the digital version for instant download.
https://www.bearpawproductions.com/s...ngulations.htm