Aromatherapy can be used for just about anything, and there are tons of books out there on combinations of oils that are meant to achieve different results. One of my favorite tomes on the subject is The Complete Book of Essential Oils and Aromatherapy: Over 600 Natural, Non-Toxic and Fragrant Recipes to Create Health, Beauty and a Safe Home Environment by Valerie Ann Worwood.
Be sure that when you're using essential oils on skin, you dilute them with carrier oils (jojoba oil is a nice, light oil that won't mask the scent at all—though any light oil will do). Essential oils have been distilled down to their most potent form and often will have alcoholic content, which can burn your skin if not adequately buffered with a carrier oil. These additional carrier oils will also help make sure that your essential oil lasts you a long time—a little bit of scent goes a long way in terms of achieving results!
Also, whenever you're ingesting an oil or putting it on your skin, make sure you're using quality stuff. Some companies have been known to dilute their oils, which you don't want. Your local health food store clerk can help you pick out the top-quality essential oils. When purchasing online, make sure you stick with established brands. I love Young Living essential oils, though any top-quality brand will do.
Daphne Oz is the author of the national best-seller The Dorm Room Diet and The Dorm Room Diet Planner and creator of the Dorm Room Diet Workout DVD. She is the daughter of Lisa and Dr. Mehmet Oz.