Before each lighting, trim the wick to 1/4 inch. This prevents a large flame, smoking, and uneven burning 

Allow the candle to burn for at least 2-3 hours, or until the melted wax reaches the edge of the container, creating a "memory" for future burns and preventing tunneling.  

Letting your candle burn for too long can also be problematic. This can lead to your candle overheating, which in turn thins the wax. As well as damaging the fragrance oils and causing your candle to put off soot, your candle may slant and burn unevenly. 

Place the candle on a heat-resistant, stable surface away from drafts, flammable objects, children, and pets .  Of course, a strong breeze can blow your candle out. But even gentle wind from a draft, window, or air vent can cause the candle to burn quickly and unevenly. So if you see the flame flickering, put your candle somewhere else or utilize a hurricane glass container. 

One of the best candle care tips that many people don’t follow is retiring a candle while it still has wax left. This is important because burning a candle all the way down can overheat and damage the container, which can create serious mess. Instead, replace your candle while it still has around ½” of wax remaining to protect the container and save yourself some hassle.