The biggest mistake I ever (not that I have a long history?) made making a quilt was stippling a fairly large lap quilt too close together and also in close quarters. I was almost at completion and found that the backing had several folds in it, and I had to rip out all of those tight/close stitches. It was a nightmare but I fixed it and completed it--whew!!! Hubby is now working on a sewing room for me and I will not make anything larger than a small wall quilt until it is done.