I like to cut my hanging sleeve to be 5 or 6 inches times the width of the quilt(30 in your case) and then fold an inch to an inch and a half widthwise on each side and sew it down..then fold in half lengthwise wrong sided together and then sew it down raw edges together to the back of the quilt with an 1/8 inch seam.once you sew the binding on the stitches for the sleeve are covered.
Hope this helps you, good luck.