I have found that most people end up with rippled borders because they don't measure the quilt before cutting the borders. That's the way I used to do it. Just cut a border and start attaching it. My LA quilter was the one who told me I needed to measure before I cut the borders and I wouldn't have that rippling and her work would be easier. Don't have any problem any more. I do pin when putting my borders on. I pin at each end, in the center and at the quarter point at least.