One other hint that I don't think anyone has mentioned yet. Now that you have your circle jig, make the first shallow pass to define the circle. Then use a hand-held jig saw to cut the waste off. Follow the groove you just made, making the cut just outside of the inner edge of the groove. Then make subsequent passes with the router to clean up the edge. This way you get rid of the rough waste before cleaning up the cut. If you already knew this, please ignore that man behind the curtain!