I used the tutorial from Sharon Schamber and it was amazing. I had to sit and do it with the computer right next to me, stop, rewind, really study the technique, but it's absolutely spot on for accuracy. It's amazing. I just made a bunch of HST's and they were as close to perfect as anything I've ever done. Not a single one was off, stretched or anything.
Using this, the first set took me quite a while because I kept watching and rewinding to get what she was saying, but once I had it down, boy, they went quickly.
the video is for "Sharon's Magic Triangles"
Have fun!