After I've finished quilting and cutting away the excess batting and backing, I machine baste with stitch length set at the maximum, 1/8 in. from the edge of the quilt. Then I gently pull a stitch here and there, maybe 4-5 inches apart, to make a very gentle "gather". I stitch on the binding with my walking foot, taking care not to pull anything. This method works very well for me. No wavy binding. And the "gather" sort of flattens out when stitching, so it's not apparent.