I'm learning how to machine quilt and wondering: how do you handle it when you make a mistake? If you are trying to quilt with few starts, to reduce the number of knots that must be hidden; does that mean you rip out half your quilting if you make a mistake? If not, how do you tie off prior to the mistake? Resewing a few seams is disheartening, but the thought of requilting half a quilt is enough to make me cry!