not sure how u would addapt it but
1. I make perfect circles but cutting one circle in desired fabric and one circle to match either out of matching fabric of coordinating or muslin.
2. Place right sides together...
3. stitch around circle, yes ALL the way around
4. on wrong side, I cut a small slit ( careful not to cut the desired fabric
5. clip edges
6. birth circle thru slit
7. press right side of fabric
8. applique or whip stitch to desired area
Nice round edges....
I made an entire quilt using this method