There are two ways to clean our beloved brushes (of course you know about that, I'm just playing ms-know-it-all LOL). Deep cleaning and spot cleaning. I'm gonna show how I do the first one. =)
I deep clean my brushes at least once or twice a week, at night before sleeping. I let them dry overnight so they'd be ready when I want to use them prepping up for the following morning!
Here's everything I use to deep clean my brushes.
A sponge and a baby shampoo:
Wet the sponge and squeeze it. Then pour a bit of shampoo (i put too much in this pic). Wet the brush and work it on the sponge, just swirl it on the sponge. Take note though that I do the swirling thing for round brushes like this one (that's my etude dual fiber brush after using on my NYX Rouge Cream blush in hot pink), for flat brushes like the foundation brush, blush brush, etc., I do the sweeping motion back and forth, I'm not sure of the term really, but I hope you get what I mean =)
See how the dirt/stain transferred from the brush to the sponge? You'll know when to stop when there's no more stain coming out of the brush.
Rinse under running water. Make sure to point the brush downwards. I prefer brushing it on my palm. I don't know why hehe. I'll know I've rinse it enough when the drips of water coming from the brush is already clear.
Remember to avoid having water get into the metal part (ferrule) of the brush, or specifically on the part where the metal and the wooden handle meets. Water in the ferrule can cause the glue to loosen around the hair of the brush. We do not want that of course!
Gently queeze the water from the brushes, again point downwards. Reshape the brushes. Where's my nail polish!?!!?!
Lay flat the brushes on a towel (or on a paper tissue if you want) for drying. I use an aquazorb towel. I bought this towel last year but I don't like using it on my body as I prefer 100% cotton, so I use it instead for my brushes, and it's the best haha!
I normally fold one side of the towel so that the brushes are a li'l bit tilted. I noticed that they dry faster this way, and it also made me feel assured that no water will be in contact to the ferrule. After drying, I wipe the handles and the ferrule with a tissue.
Avoid drying the brushes under the sun and also, don't blow dry them, you'll damage your brushes, they didn't come cheap, remember! I also use a new sponge every time I deep clean the brushes.
A few months ago, I used to say, cleaning brushes is therapeutic for me. Not anymore haha!