When I made the crazy patch for my heart sampler, I tried to use as many heart-related stitches as I could, including an experiment with chain stitch:
Make a row of very loose chain stitch, going from the bottom up:
Once you get to the top, go back down working tacking stitches to shape the hearts -- one on each side, a little above the insertion points in the fabric:
Continue all the way down to make a chain of hearts!
While searching Pintangle's Take a Stitch Tuesday archives for another project, I came across a chain stitch variant called shell chain stitch. That pretty stitch plus the hearts inspired me to start a chain stitch sampler: