Candle lovers, listen up: If you’ve ever encountered a candle that only melts around the wick — called “tunneling” — there’s an easy solution that can give you a perfectly even candle line once again.

Whether you're melting down old candles or starting with fresh wax, candle-making is easy. Essential oils are the purest form of fragrance for candles, but fragrance oils smell stronger. Soy wax, ...