I have never used a walking foot to apply binding, but I've never had a problem with my binding puckering either. I am by no means a very experienced quilter, so I can't really speak to the issue. What I do -- unless I am doing bias binding, I cut my binding lengthwise of the grain, fold it in half, press, and pin to the front of the quilt, stitch it on, fold over the stitching, hand-stitch to the back side of the quilt, being very careful NOT to stretch the fabric!