A while back I placed an order at My Crochet Shop. When my order arrived there was a cute little crocheted heart used in the wrapping. I held onto the heart because I knew I could use it for something. I ended up turning it into a sweet ring that would be perfect for an affordable Valentine's Day gift. The owner of My Crochet Shop on Etsy also has a wonderful blog. If you would like to make yourself an interchangeable heart ring, first check out her crochet heart pattern here.
These would make great favors at a girly Valentine party since you could use them as the napkin holders.
Here is what you need for an Interchangeable Heart ring: