It is REALLY important to clean your brushes regularly. Most people say once a week is sufficient, but some (like me) will need to clean and disinfect much more often. WHY? Because brushes can be a host for bacteria and also hold onto dirt--causing clogged pores and acne in some cases. I tend to be a little over the top with my brush cleaning. As a makeup artist, I can't take any chances... I spray with disinfectant in-between clients and wash all brushes before and after every job.
How to clean your brushes...
I (like many) routinely clean my brushes with baby shampoo. It's gentle and does the trick while preserving the hairs on the brush. Sometimes I use a clarifying shampoo just to get a little deep cleaning...I would say once a month. Most people say you should "wash your brushes twice in baby shampoo." While that is probably an ok approach (remember, I am a little over the top), baby shampoo doesn't disinfect--it only cleans. So, on the second shampoo, I use an antibacterial hand soap just to be safe.
Squeeze the excess water from the brushes, making sure you preserve the shape of the brush. Lay flat (overnight) to dry.
Extra credit: for natural hair brushes--conditioning your brushes once a month is suggested.
Brush Cleaning tips:
DO NOT... Soak your brushes--you can loosen the glue in the ferrule (the metal piece that connects the brush head to the handle)
When using a highly pigmented color (like Ruby Red Pigment or Night Star by MAC) clean your brush right away--these colors can bleed off on the next application, creating a mess.
Never stand your brushes up to dry as this can damage the glue in the ferrule also.
Make sure you reshape your brushes when they are wet.
Megan Can be contacted via http://MeganMelone.com