I use template plastic and a circle template (it comes on a rectangle of various size circles) from the office store. So, I trace the circle onto the plastic with a Pigma pen and cut it out. Then cut a little bigger circle of fabric (using the circle template to trace that too). Using a double thread, take small running stitches along the outside edge of the fabric, and leave the tails. Position the template plastic circle in the middle of the wrong side of fabric. Pull up the thread around the plastic. Iron the circle and starch it. Then remove the plastic. It makes a perfect circle.