Central Ohio Quilter

I want to appliqué circles with shadows on a quilt.

Have you you ever done circle shadows? Do you have any hints or advice for making the shadows lie flat and look great? How did you cut the shadows? As a half a circle, or just as a crescent? How did you appliqué them? Did you line them with a thin fabric backing or just appliqué the shadow?

i have had some trouble with appliquéing circles before and I am looking for the best way!

Thanks for any help and ideas!