|I was making some circle handkerchief hem tps using chiffon. I found it difficult to mark and cut the waist cutouts. I usually pin-mark or chalk mark my arc. The chiffon was moving on me and difficult to mark the way I usually do. I ended up making a 1/4 circle template with the corner of a piece of cardboard. I want a circumference of about 43", so my radius needed to be 6-1/2", allowing 1/2" seam allowance. I marked and cut out my quarter circle. I was able to control the chiffon from wiggling around with the template. I could also use the edge to cut around with my rotary cutter.
I could still use this template for other radii by moving it in or out on the diagonal. For instance, If my waist radius needed to be 6", I would move the template so that 1/2" was hanging over on each side.
another picture of cutting chiffon with template