Dirty Makeup Brushes.
How many times have you said to yourself “I’ll clean my brushes tonight” and then never get to it? Unfortunately for the procrastinators, soiled makeup brushes are a big cause of breakouts. The bacteria your brushes collect from daily use is dangerous for your delicate skin.
Break the cycle:
After every few uses, swirl your makeup brushes in rubbing alcohol. The alcohol kills bacteria and also gets the white tips of brushes back to their pristine state. Also, remember to deep clean brushes and sponges with baby shampoo or a bottled brush cleaner every week. Lay brushes flat to dry and allow them to dry completely (ideally overnight) before you use them again.