When I machine applique, I used fusible interfacing. Cut it out the same shape as your appliqué. Put the right side of fabric to the fusible side of interfacing, and sew around the perimeter. Cut a slit in the interfacing, and turn it inside out and finger press it, and push the corners out. The right side of fabric is up, and the fusible side is down. Press the applique piece in the correct position on your block or quilt, so that is fuses to the base fabric. Then, I use a blanket stitch to sew the edges down. And, as in the case of leaves, I use a decorative stitch down the center . Carolyn