Match the wick size to the diameter of your container rather than using whatever wick is on hand, since a wick that's too thin won't melt the wax evenly to the edges, while one that's too thick creates a large flame that smokes and burns unevenly. Heat wax to the specific temperature the wax manufacturer recommends before adding fragrance oil, since adding scent too hot burns off the fragrance before it sets, while adding it too cool prevents it from binding properly with the wax. Let the candle cure for at least 24 to 48 hours before burning it, since wax and fragrance need time to fully bind and harden, and burning a candle too soon often results in poor scent throw and an uneven burn pool. Trim the wick to about a quarter inch before every burn rather than leaving it long, since a long wick creates a bigger flame that produces soot, a mushroom-shaped tip, and uneven melting. Center the wick and hold it in place while the wax cools rather than letting it drift, since an off-center wick causes the candle to burn unevenly and tunnel down one side, wasting wax on the other. Work in a well-ventilated space and never leave melting wax unattended, since wax can catch fire if it overheats past its flash point, and this happens most often when wax is left heating without supervision.