You might want to search the You Tube.com website for lessons on Needle Turn Applique. There a so many different ways to do it. Any time you hear someone say use freezer paper, translate that to...make a template out of card stock or even a cereal box and trace around the template on the right side of the fabric. You can also draw your design onto paper, hold up to a window and trace it onto your fabric. Use whatever type of pen/pencil/chalk (not ball point pens) that will show the line the best. As you turn under the edge, just make sure the line does not show.
As you start stitching, don't turn under anymore that a stitch or two at a time, that makes for smoother edges.
Hope this helps,