Candles—with their soft ignited glow—add ambience to any space. Place them in a dimly lit room, and the flickering light creates a soft, welcoming atmosphere. And their fragrance adds a signature scent to your home. If you have a favorite candle (or you’ve taken quite a bit of care in making your own collection of candles), you will want to enjoy their light and fragrance for as long possible. And, as candlemakers will tell you, there is a proper way to burn your candles so that they last longer.

We don’t usually consider how a chosen candle suits the size of a room, but it can make all the difference. “If you have cathedral ceilings, a 4-ounce candle will not throw the scent wall,” says Megan Piorek, owner and candlemaker at Candle Threads. The same holds true for a small room—you don’t want to overpower a bathroom with a large candle when tea lights would be perfect.

Upon first use, always burn your candle for a few hours. This allows the top layer of wax to fully melt, ensuring an even burn at the next use. After that, Piorek advises that you should only burn your candles for three to four hours at a time. “This allows the candles to burn properly, avoiding tunneling,” she says. Uneven melting of the wax is referred to as “tunneling” and makes your candles look less appealing. It also wastes the wax and can even hurt the candle’s ability to light. Stick to three to four hours of burn time if you want to avoid candle tunneling and prolong their use.

Flame-lit candles do not burn the entire candle, as the wick burns out before the wax is used up. A candle warmer will melt all the wax and will also last longer, as the lower heat will break down the wax at a slower rate.

A candle is only as good its wick. This braided cotton that holds the flame should measure about 1/4 to 1/8 inch high in order to produce an ideal burn. “Trimming the wick is important,” says Piorek. “Before each burn, trim the tip of the wick, just a little.” It also helps the candle to burn cleaner. Simply extinguish the flame, let the candle come to room temperature, and use a candle wick trimmer tool to cut down the wick before relighting. It’s recommended to do this every four hours of burn time.

Keep in mind that a candle in a container takes about two hours to completely cool down, and it’s much safer to trim the wick when the wax pool has hardened. A hot pool of melted wax can burn your fingers if you reach for the wick before it’s cooled and solidified. Another suggestion? While the wax is cooled but still malleable, reposition the wick to its wax center—this prevents soot stains from forming on the glass.

That candle might look pretty sitting near an open window, but it can reduce it’s life. According to Piorek, currents of air can cause an uneven burn. Place your candles away from areas of the house that tend to be drafty or, if you’re outdoors, keep your citronella candles or sand candles guarded against the breeze. Wind has a tendency to blow out the flame or knock things over. “Most importantly, never leave a candle unattended,” Piorek says. Not only is there a risk of fire when candles are forgotten about in a room, but you also run the risk of burning the candle for too long. You can alternate your candles to prolong their burn time—just don’t set it and forget it.

Whether or not your candles are in use, know that the wax can—and does—melt in extreme heat. “In the heat, candles will start to sweat,” Piorek explains. “Keep candles dry and in normal room temperature.” Don’t store your candles near other heat sources, such as kitchen stoves, the fireplace mantel, or the attic. The best place to store your candles is indoors and away from direct sunlight. After each use, clean the wick’s centered wax pool of any soot or charred debris using a wet cotton pad with warm soapy water. Enclose the lid to prevent dust from settling on the surface, and let it cool until it’s ready to be lit again.