I have so much fun teaching applique...I know sometimes making a circle when appliqueing can be a bear. Hopefully this tutorial will take some guess work out of the process. It a very simple process and the result will be a perfect circle every time. This method would work for any size circle.
Cut the desired size circle out of a thin cardboard or card stock.
Trace circle onto fabric using the template just made. I used a Pilot Frixion Pen which draws a nice dark line and disappears with heat. Roughly cut circle out leaving at least a 1/2" of fabric beyond pen line.
Lay template onto circle.
Using an iron, press edges of fabric over edge of template.
Continue around circle until all edge are pressed over.
Using a sewing machine or needle and thread, sew a basting stitch around the edge of the circle. A basting stitch is a very big stitch. One in which can be snipped and removed very easily. Also, trim seam allowance down to 1/4" if desired...this removes some of the bulk to the circle.
Press circle with iron...now it's all ready to applique to a piece of fabric.
After appliqueing circle to fabric, very carefully remove basting stitch.