Ensure that the first time you light your Candle you allow it to create a full melt pool, all this means is that the melted wax reaches the outside of the tin. Candles have a "memory" and the better you start the candle the more you will get out of it. This could vary between 3 and 4 hours.
Make sure to trim the wick of your candle prior to each relight, this will help it to burn evenly and for longer. It may produce a slight "mushroom" if not cared for.
Do not burn your Candle for longer than 4 hours.
Keep the wax pool clear of any debris, this may include bits of the wick or match heads.
Keep away from any rooms that tend to attract the wind or any places which attracts draughts.