I have witnessed 2 miracles this week: Sta Flo Starch (Heavy) and Bloc-Loc Ruler!!!
Yes, I know this sounds tongue and cheek and my appologies if it sounds offensive but I am completely serious.
I had been using the Sta Flo starch for a few weeks at about half strength but decided to try something stronger and wow, wow, wow. The fabric behaves so nicely at every step--when cutting, when handling and when piecing. It made a huge different in the accuracy of everything. Truly amazing.
The Loc-Bloc rulers for trimming half square triangles are really, really great. While I don't keep the ruler placed and spin my fabric (I prefer to pick up my fabric and reposition the ruler), they live up to every single praise and promise I have heard. The amount of time it takes to make sure your diagonal line on your regular ruler is positioned just over the seam line and hold the ruler still so it doesn't move around is completely eliminated!!! And, the lines to measure the bottom and right side of your square are really nice fine lines--very easy to see that you are right on the edge--not like the thick yellow lines that are on the omigrid rulers that I have. I can't say enough good things about this ruler. I purchased the 3 pack of 2 1/2, 4 1/2 and 6 1/2 but quickly discovered that I really only need the 6 1/2 ruler as I like to have enough room for my palm and fingers to spread out holding the ruler down and then not feel like they are right at the edge and in danger of being cut by my trimmer.
If you struggle a bit with trimming HST or just want to make the process much more efficient, I highly recommend this ruler. Now, I am hoping to see if I can use it on a hourglass block and have good results.