8. Work on getting healthier hair even when you sleep. For those who color and heat-style frequently, a night repair serum can mean the difference between a bad-hair day and a good one (the next morning). It fills in porous hair (caused by dying) and balances out oily and dry scalps. Use it several times a week to see the greatest results. A product to try: Ted Gibson Goodnite Hair Repair Serum, $200; available at sephora.com.