Norah,
You will need a template (freezer paper, Templar or washer); can of spray sizing, paint brush, iron, and quilting thread.
I have taken several applique courses from Karen Kay Buckley, so the circle method is from her. I have nylon or teflon thin white washers in many sizes, however a stack of three layers of freezer papar will work as well or you can use Templar (which works with heat).
Draw and cut out your circles. If you use Templar use an emery board to smooth the edges. Using your template, draw the circle on the back side of your fabric. If you are using the freezerpaper method, press the template to the back. Cut the circle out with a 1/4" seam allowance. Stitch a basting stitch, round as you would for a yo-yo. While holding onto the thread tail, draw it up tightly around the template, dab it with sizing, still holding the tail, hit it with the iron. If you have any points, just repeat the process. Once your circle is dry, gently remove the template and redraw. Ready to stitch.
If you wish, you can stuff slightly for a raised circle.
For my smallest circle, I used a paperpunch to size my template. They were perfect. And I also use this method to make leaves and other shapes. The tips of leaves are perfect. I find this method much faster and more precise than needle turn.
Let me know if this is not clear. Suzanne