I just recently finished a top making 5 point applique stars like yours. And because I am a glutton for punishment I made them out of flannel! As a result some of my star points are not real pointy but they are fine for the folkart look of this quilt. I used freezer paper on the back of each applique piece. Then I sprayed the front of each star with a 50/50 dilute of sta-flo starch and water and let it dry (mostly, I found the fabric a little more cooperative if it was just a wee bit damp). Then I turned the edge using the FP as a guide and something with a bit of resistance to help me with my turning and ironed the seam allowance in place. The heat of the iron dried the stach the rest of the way. The starch held the seam allowance in place wonderfully and they were pretty stiff so I bet they would behave themselves for machine stitching in place to your background fabric. I peeled off my freezer paper and hand sewed them to my base fabric. But I could not re-use my freezer paper template. Spraying with the starch compromised it too much for reuse.