I use glasses with 3/4 water and a little oil on top , depending on how many hours i want it to burn. I use the small floating wicks with the red wicks not the white as they burn out too quickly. I use many candles… and stay up until everyone has burnt out. Every once in a while they splatter. It depends on the oil, use olive oil only if it is mixed , not pure it has different smells and does not work as well and gives off black smoke and makes the ceiling black (thats what happened for a while when i bought a big tin of olive oil from national liquidators on sale of course) I love using oil as it is clean and neat. Do NOT fill up with oil otherwise it gets too hot and then you hear crack and the glasses break , i learnt my lesson the first couple of yrs.
Also when you light the wick do it that one drop of wax falls on the cork to make it stay in the center. have a good shabbos and bring much light into this world.