Most of us grew up drinking our milk out of jelly glasses. But using the jars that way neglects one of their most useful properties: the ability of their thick, tempered glass to withstand heat. Antique jelly jars are perfect vessels for scented candles, which make wonderful gifts.
To begin, fix a wick with a metal wick tab to the bottom of a jar using plumbers' or wick putty; suspend the wick from a pencil laid across the top of the jar. Place some bleached beeswax (1 pound fills four or five 8-ounce jars) in a double boiler, and heat to 135 degrees (check with a candy thermometer).
Remove wax from heat, and stir in about 50 drops of a pure, oil-based plant essence, such as lavender, sandalwood, or jasmine. (The exact amount will depend on the oil's intensity and your own preference.)
Pour wax into jars; set jars in a cold-water bath to cool. Add more wax as needed.