When I was in makeup school(many, many years ago), my teacher at the time always stressed the importance of keeping your makeup brushes clean and moisturized. To preserve your brushes and to last a lifetime, it is crucial that you give them a good wash one a week. Whether you are washing brushes for professional use or your own personal use, I always suggest a very mild and moisturizing shampoo. Another great option is a gentle foaming cleanser for face. When washing, please be gentle. No rubbing or squishing the bristles. Use luke warm water and after rinsing very well, drain most of the water out, reshape the brush (crucial step), lay it flat to dry. Preferably on a towel. Taking care of your makeup brushes will give them a longer life and helps to keep germs and bacteria at bay.