The first time you burn your candle it is important to burn the candle until the wax pool reaches the side of the jar (approx 1-2 hours).  This first burn will form a 'memory' for all future burns and prevent tunnelling.  Tunnelling is where the wax pool forms a tunnel down the centre and doesn't reach the sides of the jar which means your candle will not last as long.
Always trim the wick to about 6mm above the wax before re-lighting.  Long wicks can cause excess flame, smoke, leave soot on the glass jar and an excess of carbon build-up on the wick.  

To extinguish the candle and prevent soot being blown on the glass jar, use a wax dipper to gently dip the wick into the liquid wax extinguishing the flame and then stand the wick upright again.

Only burn candles for 3-4 hours at a time.

Never leave a candle unattended or near children or pets.

Make sure your candle is resting on a heatproof surface and is kept away from flammable materials like curtains, bedding, books, paper, carpet etc.

Keep burning candles away from any drafts, open doors or ceiling fans as this can lead to uneven burning and flame flare-ups.

Stop using the candle when only 1cm of wax remains at the bottom.  Otherwise the jar can overheat and crack.
The candle jars and lid can be reused and make great containers for jewellery or bits and pieces.  Gently scrape the leftover wax out. The wick tab can be removed by soaking in white spirits for a day or so or gently removing with a wooden stick.