It is recommended you clean your brush once a week. Dampen it, then apply Estee Lauder Makeup Brush Cleanser to brush hair. Use your fingers to work into a lather (In a pinch you can use baby shampoo or a mild cleanser.) Rinse well, then blot excess water with a paper towel and reshape the brush. Lay brush flat to dry. Place at edge of table or counter with bristles pointing out to air-dry completely. Avoid drying upright, which can cause bristles to spread and handles to crack.