Aromatherapy is a way of training your body to react a certain way to certain scents.  For example, Lavender is a well-known scent for relaxation, but for some people, something like Bergamot would work instead because it reminds them of their childhood home.  Too, scents in the form of incense or candles are often used in spiritual ceremonies, as well as being a great way to hide cat ownership from your landlord!  India Temple Incense works amazingly for covering up pet odar with something clean-smelling.  East Meets West carries incense, candles, perfume oils, essential oils, and fragrance oils to soothe you and to help you control your life.