To prevent uneven wax, always burn candles long enough for the wax to melt and pool to the edges of the glass. Burning for less time can cause a build up of wax around the vessel's sides.
Trim your wick to 5mm before each burn to ensure your candle stays pristine and elegant. Long or crooked wicks can create high flames, smoking or sooting.
Keep your burning candle away from fans and air conditioners. Positioned near moving air can reduce the burn time and can disturb the flame, leading to diminished scent throw.
Burning for too long can cause the wick to move or slant. If a flaming wick comes close to the vessel wall it could cause it to crack. Extinguish the flame and straighten the wick.