Before quilting, I secure the outer edge of the quilt with a machine basting stitch. I trim before sewing on the binding to be sure everything is straight and square. If the trimming cuts off some (or all) of my basting stitch, I re-secure those areas to make it lie flat and help the binding go on smoothly.
If I plan to secure the binding by hand, I sew it to the front, fold to the back and finish by hand. On kids' quilts or something that will receive a lot of wear and tear, I sew the binding to the back, fold to the front, then machine stitch it down on the front with a decorative stitch...usually a serpentine stitch.
I like my batting full.
Anita