I press the binding in half and trim the backing and batting to 1/4 inch before sewing it on the front of the quilt. After sewing the binding on, I trim the back and binding to the edge of the quilt. Then I turn the binding over to hand stitch it. To turn a corner, I sew the binding 1/4 inch from the edge of the corner, then turn the binding up, making a triangle. I use a one inch ruler to turn the binding down, and have gotten crisp corners that way. This is how I was taught by a quilting teacher and it works for me. Oh yes, I do not clip the thread when turning the corner, just raise the presser foot, then make the turn. Then trim the edge before turning the binding to the back. One other tip. I wrap the binding tightly around a core from TP and put a long string or yarn through the core I tie a knot and slip it over my head, keeping the binding from laying all over the place. Winding it tighty is the key.