I just recently finished a D9P and used an orange peel design to quilt it. The curve was gently enough that I used my walking foot to do it. If you quilt it in rows like a giant serpentine and go one way and then reverse the process and go the other other way crossing over the stitching so the curves face each other and you do it both horizontally and vertically then you end up with an orange peel pattern. I wish I had a picture to show you but I don't. If you google orange peel quilt pattern you will find the shape. I have a tool for making curves but you could also use a plate to mark the curves. I used a water soluble marker to mark the lines to quilt on. There is no turning needed of the quilt by using this method and you don't need to free motion, just use your walking foot.