Crafts stores offer a wide array of candle molds -- they usually come with instructions on the gauge of wicking and amount of wax required. You can also use household items as molds, such as small baking tins, milk cartons, and cardboard paper-towel rolls. Or, you can use decorative objects such as finials to make your own mold.
Prepare your mold by fixing a length of wick to the bottom with a screw and a bit of putty. (These usually come packaged with store-bought molds.) Place a toothpick, pencil, or stick across the top of the mold. Pull the wick up the center of the mold, and tie it to the stick.
1. Melt paraffin or beeswax in a double boiler. When wax reaches 200 degrees on a candy thermometer, lower heat, and add synthetic hardening crystals. Use 1/2 to 1 teaspoon of the crystals per pound of wax.
2. To tint the melting wax, stir in bits of wax-dye pellets until dissolved. Test color on a cookie sheet. Fill prepared mold with melted wax to 1 1/2 inches below the rim.
3. Place the filled mold in a cold-water bath -- a bucket works fine. The water should be level with the wax. Let mold sit for 30 minutes. As air bubbles rise, a small well will form around the wick. Insert a long, thin instrument, such as a knitting needle, into the well to allow air bubbles to escape, then fill the well three-quarters full with more melted wax. Repeat the process after 45 minutes, then remove mold from bath. Allow mold to harden for eight hours, turning it periodically to ensure even cooling.
4. Remove wick screw and putty, then gently pull candle from mold. With a knife, even off candle bottom, then polish it by rubbing rough spots on a cookie sheet heated over a stove burner. For a beveled edge, quickly run the candle's edges along a hot metal bar.