Well learning from experience, I over-cut squares for HST...If it calls for say, 2 1/2", I cut at 2 5/8" or even 3", then trim to size...Takes a little bit longer to do, but safer. Always make sure your 1/4" seam is a scant 1/4".. Even if you sew a 1/4" seam, the thread takes off a little so takes off the true size of the HST. I always 'try' to make sure there is a 1/4" at the edge so when you sew block (pieces) together, you have a seam width there so as not to sew off a point. I hope this helps - I'm sure others have other ideas. I like your blocks, very pretty.