21. The Non-Drying Shampoo — All those pretty coiffs call for piling on the styling product, which means tons of build-up on your strands. A clarifying shampoo will help remove the dirt, excess oil, and product residue from your mane without stripping it of the hydrating natural oils it needs to stay healthy and supple.

Rene Furterer Forticea Shampooing Stimulant, $28, available at Dermstore; Malibu C Un-Do-Goo Clarifying Shampoo, $13, available at Malibu C.