Wicks can be trimmed to 1/4 inch before relighting, if needed. The best way to extinguish flames is by placing lid on candle.
Precautions: Burn within sight. Keep away from things that can catch fire. Keep out of the reach of children and pets. Container may be hot when the candle is lit. Keep all objects such as matches and wick trimmings clean from wax. Do not burn candle for more than 3-4 hours at a time.