Q: Dear Matt, my pillar candles burn evenly and become lopsided. How can I prevent this?
A: I suppose you could carefully guard the wick to make sure it doesn't get to long, patrol the melted wax to make sure the solid to liquid ratio of the wax is correct, and keep the candle away from persistent draft.
On the other hand, it's a great deal easier if you never light the candle. It will never burn unevenly then.