This DIY project is cheap and easy, and ensures that you won’t have a room full of synthetic fragrance.

The purpose of an essential oil diffuser is to spread the aroma of essential oils throughout a home, deodorizing and purifying the air, making a room smell great, and lifting the mood. Some require electricity to heat the essential oils, while others use reeds to diffuse the aroma. Many diffusers, unfortunately, contain artificial fragrances or carrier oils whose phthalate-laden fumes are less than healthy and defeat the purpose of creating a sweet-smelling, purified, and energizing space.

It’s best to stay away from commercial versions and to make your own essential oil diffuser. That way you’ll know exactly what’s in it. It is quick and easy to assemble, using household materials that you’ve probably already got. They will not smell as strong as the commercial varieties, so they’re best kept in a small enclosed space, like a powder room, walk-in closet, or small office. You could try grouping several diffusers together to fill a larger space.

Choose a Container

Select a jar or container that has a narrow opening. Glass or ceramic (glazed on the inside to prevent leaking) are attractive options. Small vases or repurposed spice jars work, too. Visit a local thrift store for a range of options. If there’s a cork in the top of a jar, just drill a few holes through it to place the reeds.

Buy Some Reeds

You’ll likely need to buy reed diffuser sticks at a craft store or get something else to serve the same purpose. Bamboo skewers work, after cutting off the pointy ends, as well as unfinished balsa wood, chopsticks, or rattan chair caning, which curls attractively (learn how to do it here). The narrower the material, the easier it is for the liquid to travel up it. Make sure the sticks are twice as tall as the container to help diffuse the scent.

Decide on a Base Liquid

There are a few different versions for the base liquid, which may be determined by the type of homemade diffuser you want and which ingredients you have on hand.

1. Alcohol + Water + Essential Oil

Alcohol evaporates faster than water, which makes it a good option for drawing the scent up through the reeds. It also won’t make a greasy mess if it gets knocked over, unlike the oil-based version below.

Pour 1⁄4 cup of hot tap water into an attractive jar or container. Add 1⁄4 cup alcohol (I used rubbing alcohol, but apparently vodka works, too) and 20-25 drops of whatever essential oil you want to use. Swirl to mix.

Note: You may want to use distilled water or cooled boiled water, as these will last longer.

2. Carrier Oil + Essential Oil

A ratio of 30% essential oil to 70% carrier oil is recommended. Avoid mineral oil, as it’s a petroleum-based product. Regular vegetable oil is far too thick and will not work at all. Try sweet almond or safflower, which are oils with minimal scents. Add essential oil and swirl to mix.

3. Carrier Oil + Alcohol + Essential Oil

Use 1⁄4 cup carrier oil (sweet almond or safflower) with 2-3 tbsp vodka and a generous quantity of essential oil (that 30% to 70% ratio again).

Pour any of the above combinations into an attractive glass or ceramic vase. Add bamboo skewers (cut off the pointy ends first), special diffuser reeds (order online), or some kind of dried plant material, i.e. twigs, woody stems, reeds, that will draw the liquid upward.

Soak the ends for a couple hours, then flip around. Do this a couple times a week. Top up the mixture with more essential oil as needed. Replace the essential oil mixture once monthly to maintain the scent or if it smells off at any point.

Which Oil to Use?

Lavender, lemon, and thyme essential oils have good antibacterial activity. Lavender, bergamot, and sandalwood help combat depression, while yuzu helps to inspire a positive mental state. Lavender, geranium, roman chamomile, and ylang ylang can reduce tension. Peppermint can energize.