Three basic methods for using essential oils

Inhalation

Inhalation is the most common method of using essential oils and the basis of aromatherapy. You can inhale the oil directly from the bottle or pour a few drops into a diffuser, which spreads the fragrance over a large area. You can even wet a cotton ball with essential oil, and then set the fragrant cotton near you or in any area you want fragranced.

Topically

Many essential oils are used topically, which means they are applied to the skin. However, since essential oils can be irritating to the skin on their own, the essential oil is should diluted with a carrier oil before it is rubbed into the body. Fractionated coconut and jojoba oil are the most common types of carrier oils.

Internally

Occasionally, essential oils are added to water, juice, or foods and ingested. But while a drop or two of lemon essential oil is a nice way to add taste to a glass of water, regular or intensive ingestion of essential oils is not recommended unless you are advised to do so by a holistic expert or medical professional.  Beware of companies that recommend ingestion.