Take a look at these tips for creating Chocolate Hearts:
Try This Technique:Step 1.
1. Using a double boiler helps prevent scorching the chocolate. Place water in the bottom of a double boiler so that it comes to within 1/2 inch of the upper pan (water should not touch the upper pan). Coarsely chop 4 ounces of good-quality chocolate. Put the chocolate in the upper pan of the double boiler and place it over the water in the lower pan. Place the double boiler over low heat. To temper the chocolate, stir it constantly with a rubber spatula until completely melted and smooth. This takes 15 to 20 minutes; do not rush this process. (The water in the double boiler should not come to boiling while the chocolate is melting.)
2. When melted and smooth, the chocolate is ready to spread. Pour the chocolate onto a baking sheet lined with parchment or waxed paper and spread it evenly to 1/16- to 1/8-inch thickness. Allow the chocolate to stand until almost dry (to the point where it loses its sheen but is not completely hardened).