Makeup Brush Maintenence

Hygiene

Many people have different techniques to cleaning their brushes, and there is a massive myth circulation the beauty blogesphere that brushes should be deep cleaned every week. I don't know how true this is and I would understand that this may apply to the professionals because of the many clients they have but when I have cleaned my brushes for a couple of weeks in a row they have become awfully dry.
Professionals should be spot cleaning their brushes after every client, but personal use its OK to leave it a couple of weeks as personal brushes have only one face to tend to.

We have sebaceous glands in our skin that lie underneath our hair bed, these secrete oils such as sebum. Sebum can be describes as fatty, waxy deposits. It is what keeps skin supple and elasticated and also shiny and oily. Some say that its more beneficial to have oily skin than dry skin, as its a youthful trait to have oily skin. However any spread of oils that are not meant to be there is undoubtedly unhygienic.
The make-up that is applied to the face, will also pick up any harbouring bacteria that has been lying on the face which is why they say to apply make up to a fresh clean face, but when that make up brush is put down and then used the next day on another fresh clean face the bacteria on that brush can still be applied abck onto the face.
"But my face is clean and my brush is clean" 
That might be the case, but any bacteria that isn't on its original host can still turn into germs.
"Surely 1 day will not cause me to break out"
Probably not, which is why I think a week is too much for your brushes.

How I do it

I clean my brushes in the bath, before I put any bubble bath or cleaning products or any other bath lotions in so I know they won't get contaminated with any other substance apart from shampoo.
I clean my brushes with shampoo, and I like to use kind shampoo, such as Johnson baby or Treseme, as these don't have overpowering smells compared to herbal essence or John Frieda which is usually formulated for coloured hair.

I squirt a bit of shampoo in a petri dish/container and wet my brush up to the base of bristles, and stipple the brush into the shampoo and then scrub into the palm of my hand in big swirls.
With some bigger/denser brushes, I like to scratch in the middle of the bristles to get any make-up out.
I then squeeze the bristles from the base to the tip with my thumb and edge of forefinger, to get any wet make-up residue out. I then wrap them in a towel  and to dry them as fast as possible, I either put them in the airing cupboard, or above a radiator.