I used to buy those plug-in air fresheners. The ones that cost eight dollars and smell great for about four days. Then the scent fades, but you keep buying refills because the device is already plugged into your wall and taking it down feels like admitting defeat.

A friend who runs a cleaning business told me she makes her own. Cheaper, lasts longer, and you are not breathing mystery chemicals. Here is how.

The Basic Recipe

You need three things: a small glass jar (a Mason jar or an old candle jar), baking soda, and essential oils. Fill the jar about a quarter full with baking soda. Add ten to fifteen drops of essential oil. That is the base.

Now punch holes in the lid. A hammer and nail works, or just use a piece of breathable fabric secured with the jar ring. Set it anywhere — bathroom, closet, entryway. The baking soda absorbs odors while the oil slowly releases fragrance.

My Favorite Scent Combinations

For the bathroom: lemon and tea tree. Tea tree kills mold spores, lemon smells clean without being perfumey. For the living room: lavender and vanilla. For the entryway: peppermint and orange — it hits you when you walk in.

One jar lasts about two to three weeks before the scent fades. To refresh it, stir the baking soda and add five more drops of oil. Replace the baking soda completely every other month.

For the Car

Same recipe, smaller jar. Use a baby food jar with holes in the lid and tuck it in the cup holder. Much better than those little trees that smell like a gas station bathroom.