Photo by: Roger CabelloThe saboteur: Your shower.
Sediment from your showerhead is damaging. "Mineral deposits and rust in your pipes dull hair like nobody's business," says colorist Kyle White of the Oscar Blandi salon.
The savior: Vinegar.
Twice a week, add one teaspoon of apple cider vinegar to a cup of water and pour it over your hair after shampooing and conditioning. Wait five minutes, then rinse. The citric acid "removes all the mineral buildup," says White. For a speedier, less smelly alternative, Fekkai Apple Cider Clarifying Shampoo gets out the gunk in a single step.