I don't know that mine are perfect but they are pretty close. Only once in a rare time does the stitching come off the line. I always fold and stitch the front, that is where it matters most. I stitch the binding on the back then take it to the ironing board and press out before folding over. Then at the ironing board and fold it over to the stitching line (just a tad over the line) and put a couple dots of glue, iron and move on. The whole gluing process might take 15 minutes for a full size quilt but that that is saved 10 fold from having to rip out stitches when the fold doesn't line up perfectly. When stitching I use an edge foot and move my stitches in 6, 7 or 8 stitches - to where I'm sure I am within the stitching line on the back. Works every time. I'm also careful to fold the corners nicely and glue them in place too.