Blanket stitch is a decorative stitch can be used to hold applique in place.
Use a contrasting piece of embroidery thread and separate it, so you have 2 strands.
Thread your needle & wrap thread around the tip 3 times. Hold in place with your thumb and pull needle so it creates a quilters' knot.
Begin along straight side of the heart. Bring needle to the front at point A
Place needle in at point B Come up at point C. Make sure thread is under the needle, pull though. It should form an “L” shape.
Continue with blanket stitch until you reach the top of the heart. Insert needle at point D, make a stitch. Continue with the rest of the heart following on from point E.
When you get to the point of the heart and have made your stitch, make an extra stitch at G so you hold the stitch at the point in place. Continue to the start point.
To finish off insert needle in your first stitch, bring needle to the back and weave through stitches.