I took a class with Christine Fries Ureel last summer, and she demonstrated this technique. http://www.loveabideth.com/index.html Here is one butterfly I made in class.
Isn't it great? It was stitched in a hoop: 2 layers of fabric, wrong sides together, topped with a piece of heavy washaway stabilizer on which you draw the butterfly. Satin stitch around the outline, decorate the wings to your heart's content with your sparkliest, brightest, shiniest threads. Trim close to the satin stitching, rinse away stabilizer and attach to quilt through the body. Very pretty!