Having been faced with making over 200 HST, I tried all methods. The one where I get best results, and is the fastes overall, is by printing off the triangle paper from on line and following the directions for sewing and cutting. The bias edge is controlled by the paper (I am leaving on until I sew together) and they turn out very accurate this way. I also starched the fabric before cutting.
There is no way to create a triangle without one edge being on the bias.