Always trim to 5mm before lighting this helps the candle to burn evenly and without the black soot and for longer.
The first burn is the most important – it helps to let the candle burn for 4 hours to help the wax pool reach the edge. We always like to remind people that wax has memory, meaning that if your candle doesn't burn to the edges, it will begin to tunnel and won't burn evenly the next time.