If there is one golden rule about proper Candle use its this: TRIM YOUR WICK. Most people don’t even think about it but your wick should never be longer than 1/4″. When a wick is longer you cause the flame to burn hotter which can damage your Candle and cause it to leak or run and burn too quickly and can pretty much ruin or waste the nicest quality Candles. Before and after each use just snip the wick down.
When you first give a trimmed wick a light you should be seeing the proper flame length but after its been burning a while it will start to get too long again sometimes. For this reason its a good idea if the Candle type you are burning starts to burn hotter after a while to check it every few hours and if needed snuff the Candle out and trim the wick back down and relight it. If the wax is really loose you might want to give the Candle a break before relighting.
When you have wax that does spill over, you don’t have to waste it by throwing it away. If its scented wax you can add it to an oil burner and place tealights below it and treat the wax bits like aroma producing wax melts.
Ever get a Candle holder that has old hard wax in it? Don’t scrape it out and risk hurting yourself or damaging the holder, just run hot water over it and wait for it to begin melting to loosen the wax and either lift it out once its softer, or wait for it to completely melt.
If you have sticks that just won’t stand up straight in the holder, a neat trick is to use Candle Wax Adapters that stick to the Candle and to the holder and keep your Candle firmly in place and standing up straight.