I don't like buying rulers that have only a specific purpose. I always thought the Bloc Loc ruler was one of those rulers. I used one at a guild workshop and love it. I came home and ordered a bloc Loc ruler right away. My favorite way to make HST is the method where you make 8 at once. There are tutorials for it online.

I am working on a quilt that is made of up a lot of 2" finished squares and HSTs. I cut my HST to be 3". The HSTs come out perfectly after I trim them down to 2.5".

Good luck! I hear your frustration. I do hope you find the solution to your problem so you won't feel so frustrated.

Look like the solution is to make larger and trim down. That's what I do too. I'm amazed that so many of us find that's the way to go. I know f&P has mentioned when you sew, don't sew exactly on the line. Make room for the fabric to fold over.

I also like the 8 at a time method (here's a YouTube https://www.youtube.com/watch?v=saBKMqyw-0E) and the brilliant woman behind Sew Preeti Quilts (http://sewpreetiquilts.blogspot.ca/) has made it possible for me to finally manage a successful hourglass block. She also has a tutorial for Pinwheels that would work for HST if you used (2) four patches instead of a 4 patch and a plain square. Good luck!

Have you seen this tutorial? I'm impressed! You might like it, too.
https://www.youtube.com/watch?v=A91W0tUTFyg

I usually start with the fabric cut a little bigger than necessary and trim down to size after sewing. Might waste a tiny bit but it is easier for me.

Try thangles. Perfect HSTs every time.

http://sundaybestquiltworks.com/sten...etriangle.html

i promised myself that I would never make a lot of HST and then I discovered these stencils. I love them! I am currently working on a pattern that uses 1" size and am amazed at how simple and exact it is. My guild recently made a donation quilt with all HST. The members that used the template had the best results on their blocks by far. If you happen to order please mention that Kaye from Macon recommended this. I will be rewarded with a smile the next time I visit the shop which is about two hours from where I live.

This is my favorite method too. The other thing is handle GENTLY when pressing. Press each corner first, then the rest of the seam.