I usually cut larger for 3 1/2" I cut my squares at 4" and sew a scant 1/4" and then trim down. HST's are not my frien either tgat is why I have 2 BOM that are over 3 years old both require like 200 or more of these things.There are a lot of people who use the strip tube method I guess Missouri Star Quilt Company has a tutorial on this method.