It is important to keep makeup brush clean all the time. After all this is the tool that keep contact with your eyes and face.
It is best that we clean them every time after use and every week or month for deep cleansing.
Usually I will use tissue with spray of DIY brush cleanser to clean my brush every time after use.
I put my diy brush cleanser into a spray bottle, click here for recipe
With a piece of clean tissue, spray the cleanser into a clean tissue
Just swipe back and forward to clean your brush
After the brush is clean, leave it for 1-2 min to dry the brush