How about an applique? Just draw your own heart on a 5x5" piece of paper, then use that as a template. Easiest for a first try would probably be a raw edge applique with a light fusible underneath. Fuse it to the fabric first, then cut out with your template. Iron on the square, and use some decorative stitching on the edge. I usually use a very close zig zag. Others use a blanket stitch. Try a couple ways and use what you like best.