Hi Connie. I love curves and use them often for the motion they generate. I think maybe this is what you are looking for. These instructions are for very simple curves on each side, but if you cut an "S" curve or something more complex, the piecing works the same way if you just treat each section of the curve separately. If the curves are shallow (a quarter circle or less), I do not clip them, just ease them. And always pin and sew on the full side...that's the key!
http://outofthebasement.blogspot.com...sy-curves.html There are some great books on freeform curves by Judy Dales, Louisa Smith and Peggy Barkle. Hope this helps you.