On the first burn allow the wax to melt all the way to the sides of the container. This should take 1-3 hours. Failure to do this will often cause tunneling which can limit the life of your candle.
Trim your wick to about 1/4" before each burn. To extend the life of your candle extinguish the flame after 4 hours and trim the wick. This will ensure a long lasting candle, minimize soot and remove any mushrooming of carbon on the end of the wick.
Extreme temperature fluctuations can cause sweating. This is normal, wipe off the excess moisture, or burn you candle.