If you are going to bind the quilt (rather than birth it), you will want a bias binding. If you haven't worked much with curves, it can help to 'prebend' the binding on your steam iron by laying it on a drawn line the same size as your sewn edge. To make the rounded edge without a round ruler or template, use something that size from your kitchen - a plate, a lid, a container. A tip when sewing around a curved edge is to hold a pin at the center of the circle and let the fabric spin around under the presser foot. This will make a cleaner curve than working from the edge and constantly turning it.