Avoid draughts - they can cause a flame to be blown to one side, smoke and cause the candle to dribble.
It is a wise precaution to use a candleholder when burning a candle.
To avoid the wick being drowned on subsequent lighting, allow large diameter candles to burn for several hours before extinguishing.
On extinguishing a candle a snuffer will prevent the wick from smouldering and producing an unpleasant smell. If a snuffer is not available, gently blow the flame out and then extinguish the glowing tip with moistened thumb and finger.
Avoid placing a candle in a window that receives direct sunlight. Some of the colours fade and on hot days the candles can become sufficiently soft to sag.