Just as your body needs water to survive, your hair must replenish its moisture to stay healthy. "Conditioner for hair is like water for the body: You're always going to need it," says hairstylist Lorraine Massey. So if you're a dry-shampoo fan, add moisture, even if you're not washing. The time-saving formulas of dry shampoos are designed to soak up oil, leaving hair lackluster. To rehydrate without wetting, spritz a dry conditioner on thirsty ends every two days.