I don't know if this comes off as a little big headed telling you how I do this? I'm by no means a pro at anything to do with make up, but I just thought I'd share how I take care of my beloved Real Techniques brushes because I would have liked a post like this when I first got them.
I want my brushes to last as long as possible, but also know that it's important to clean them to avoid bacteria building up and various other obvious reasons. So that meant I needed to buy a brush cleaner. This was a whole new world to me and to be honest I kind of grudged the idea of spending money on one. I mean there are much prettier things to spend your money on, right ladies?
Fortunately I learnt that baby shampoo is gentle but effective enough to clean your brushes, before I forked out on a fancy pants cleaner. I expect the ingredients are pretty similar really. I bought good old Johnson's baby shampoo.
Cleaning the brushes is dead simple, I literally just use lukewarm water and a little of the shampoo then brush the brush about (if that makes sense!) in the shampoo in the palm of my hand. I just keep rinsing the water away and brushing about until the water runs clear.
That's it! You need to be careful not to get water in the ferule if you can help it so for this reason I try to keep my brush bristle end downwards while washing and also when they're drying. I don't know about other brands but if I wash my RT brushes at night they're always dry by the time I want to use them in the morning. They clean up really well, like new almost and they smell nice because of the shampoo.
I know other people have different ways and it's all about what works for you, but this is how I do it and it works pretty well.