To prevent your candle tunneling, leave it burning long enough for the wax to melt all the way to the edges. This can sometimes take 2-3 hours, depending on the size of your candle.
A Clean Burn
Before lighting, trim your wick to around ¼ inch in length.
This helps prevent the flame from getting too large and gives a cleaner flame.
Place your candle on a flat surface away from any hazards or flammable materials, and never leave a burning candle unattended.
Keep your candle out of the reach of children and pets.
Avoid burning your candle for more than 4 hours at a time.
Burning it for too long can cause your candle to overheat and release soot, or make the wick become unstable.