I did use the templates. It was really easy - the rectangles they say in the pattern to cut the templates out of kind of confused me, as they were too big. I could easily have cut the original rectangles the right size and just taken it from there. Basically they were 2x8.75 inch rectangles, then I used the templates only to make sure the angles were correct for everything to match up. Lined up template, put my ruler on top, and sliced it that way. Really super easy.
I'm still not great with HSTs, and almost re-did your block so the corners would line up better, but decided I needed to stop beating myself up for still being a beginner. :P
It's a fun block, though. Would be great with all sorts of different contrasts!