laurilli, you might consider looking in the videos section of Bonnie's blog, where there are teaching videos for using the Easy Angle and Companion Angle ruler, so you can see them in use. I think these are well worth the money, because they make HSTs and hourglass blocks much quicker and easier, imo. I now use them whenever I need QSTs and larger HSTs (for smaller HSTs, I use the paper method).
(I assume the videos for these rulers are still on the blog; Bonnie has since made her own ruler that combines the functions of both of those, and she now teaches how to use that, rather than the other two.)