Piece O Cake website has several videos showing how she does needle turn appliqué. They are very informative even if you use another method. I have used the same method as QuiltnNan, and it works great. The only difference is that I use Mylar Plastic Template sheets. The other thing I do is run a basting thread around the circles and draw it up with the template inside. Makes a perfect circle every time. Applique isn't a speedy technique, but so beautiful, I enjoy working on it.
Sue