Originally Posted by quiltingaz
If possible you can square up the blocks. Find the smallest one and square all others to that size. Of course this will not work if you are cutting off points.
As said above, accurate cutting, seaming, and pressing are the only real solution. Watch that 1/4 inch seam, that is usually the culprit.
Second this. I've also had 1 or 2 that for some reason stayed small, after reconstructing a couple times. So, I put some background strips on 2 sides of the small blocks and then squared them up the same size as the others. Ain't perfect but who's gonna know?!