Trimmed wicks make for a clean burn and it will give your candle a longer burn time. Trim the wick to 1/4-1/8 of an inch in length, every time you burn.
When you first light your candle, let it burn for 4 hours to allow the melted wax to reach the edge of the container to prevent your candle from tunneling. Only burn your candle 4 hours at a time.
Never leave a burning candle unattended. Place candles on a surface that can stand heat.