New design wick trimmer - Wick Trimmers are great for getting deep into your jar to trim the wick.
All candle should have their wick trimmed before each burn. A wick should be no longer than 1/2 cm - this ensures a steady flame and a better burn.
If a flame is too high or you see a "mushroom" shape on your wick. Extinguish the flame, trim the wick and re-light.