Brushes are breathing grounds for bacteria, which can cause breakouts, and cleaning them are not as simple as you think. It goes beyond simply wet, lather, and rinse. Here is how best to wash your brush.
WASH: Use hot, not warm water to keep the tools in tip-top condition. Give them a good lathering at least once a month to destroy the build-up of oils, pigments, and germs.
RINSE: Hold under a steady stream of water until it runs clear. Blot the brush with a clean towel and shape the bristle with your fingers.
DRY: Lay the brushes flat on a clean towel to dry, never stand them up. It helps protect their shapes.