Any therapeutic grade essential oil that is 100% pure (such as YLEOs) can be used in the following ways:
Direct Inhalation: pour a few drops into your hands, rub your hands slightly together so that the oil releases its full aroma, and then cup your hands over your nose and mouth. Breathe in deeply as many times as you feel it is necessary.
Diffusion: There are several ways you can diffuse essential oils
a) You can diffuse essential oils by either pouring a few drops into your hands and then slightly brushing the oil "off" onto your pillow (e.g. Lavender for a restful sleep)
b) Putting a few drops on a cotton ball or pad and then placing it next to your (e.g. RC or Raven is good for colds)
c) You can use an electric diffuser or nebulizer that dispenses micro-fine molecules of essential oils into the air. The diffuser will not heat the oil, allowing the oils to retain their therapeutic benefit and to stay longer in the air.
d) You can also use a steam diffuser where you put a few drops into the water that is heated.
Pure and Grade A Essential Oils can be used either directly out of the bottle or diluted in a carrier oil (e.g. great for massages). You can also put essential oils in your lotions, creams, soaps, or even candles.
Pure and Grade A Essential Oils can be used internally (e.g. used in cooking to enhance flavor in food. I cannot stress this enough: Please consult your physician prior to usage!
All mentioned oils can be used in aromatherapy or applied topically. Nevertheless, there is always a word of caution:
A) always (!) try out an oil on a sensitive spot e.g. the inside of your wrist to see if you are allergic before using it in a body cream. Nothing is worse then exploding in a rash after you created a wonderful cream. Further, citrus oils are photosensitive, meaning, be very careful when using these oils in your creams and on your skin. The exposure to the sunlight might heighten an unwanted reaction. Test first, then use in creams.
B) certain oils should be avoided during pregnancy, by high blood pressure, epilepsy, or diabetes.
C) caution should be used when applying to babies or children.