Hair: During puberty, a spike in hormone levels causes your scalp to make more oil. Give your hair a scrub whenever it gets greasy.
Face: Oil on facial skin can lead to pimples. Wash your face twice a day with gentle soap, and use products with benzoyl peroxide to fight acne.
Teeth: Brush your teeth twice a day and floss regularly to ward off cavities, gum disease, and (ewww) bad breath.
Body: Sweat plus bacteria on your skin equals body odor. Showering and using deodorant daily can help keep you smelling fresh.