Trim your wick with this black matte stainless steel wick trimmer!
You should always trim the wick to 1/4-inch each time before burning your candle to prevent your candle from smoking a lot (creating soot). When you receive your candle it will always be the correct height to burn it, so this is for any other future burns.
It is also to prevent the jar from getting too hot, which can be unsafe. Make sure your wax is fully dry before cutting the wick!