I'm reposting this tutorial I made a while back.
I published it at She Wears Flowers, but in case you missed it....
1. First cut out four pieces of felt in the desired shape.
I made teardrop shapes.
I've thought of making lightening bolts, hearts, crossbones, anchors-they would all be cool!
2. Then glue on the gems. These gem packs can be found at Hobby Lobby or Michael's craft shops.