In Essence aromatherapy trainer Patricia Princi-Jones talks about essential oils:

'Aromatherapy is the use of 100 per cent essential oils for therapy. You can use [the oils] in many different ways, for instance, in a vaporiser, as a hair rinse, in massage, or as a spritz.

You can apply some essential oils directly to the skin but you just need two to six drops because they are very powerful. I like a daily body rub to detox the body and firm the skin. Use a base or carrier oil - usually sweet almond or jojoba oil. Pour 12ml (or a tablespoon) of the carrier oil into a small dish. Then add three drops of lemon and three drops lemongrass pure essential oils. Dip your finger into the mixture and warm the oil in your palms before applying it. You can't apply undiluted oils directly on the skin.'