I've made several projects using neckties as a source for circles to make grape clusters.  To get the circles to remain stable as I cut and sew, I use circles from an office supply store as templates.  There's enough glue on the circles to stick to the fabric long enough to cut and sew.  I cut with about 3/16" seam allowance added, then tuck the seam allowance under to the edge of the circle as I sew with silk thread.  The circle removes easily and can be reused 3-4 times.