I love to use the blanket stitch to secure my ironed-on applique. The tricky part is going around curves for me but I set the machine to slow and keep on going. If you don't want the stitches to be noticed, use a thread color that blends and you will be just fine. Make sure you put a stabilizer behind your block so the stitches won't pull your pattern in and make it look distorted. Also, practice on a trial piece. You'll do fine!