Excerpted from The New York Times (Nancy Redd)

Most people need to clean their makeup brushes more often, and some never wash them. Dirty makeup brushes can cause various hygiene and health issues, from acne to E. coli infections. Experts recommend you clean your brushes at least once a week.

• Place a few drops of liquid soap or shampoo on your clean palm. Wet the bristles of the brush in warm water and gently rub the brush head into the soap for 15 seconds to loosen makeup buildup.
• Rinse in warm water until water is clean. Keep the water off the handle of the brush if you can. Squeeze dry. Do not pull on the bristles as you squeeze to minimize shedding and fraying.
• Dry the heads shaped properly, blot them with a terry or paper towel, and place them on a drying rack or over the sink.
• Natural bristles take more care because they are more delicate. Use hair conditioner on the natural bristles after washing them with soap, and rinse them thoroughly before drying.
• Eye makeup brushes and liquid makeup should be used every use because germs typically thrive in moist environments.
• Cleaning brushes prolong their life, and clean tools help makeup apply more smoothly.
• Store clean, fully dry brushes away from makeup, keeping bristles in your drying rack or a makeup bag. Keep your makeup bag clean and dry.