I wash my foundation and blush brush about once a week. I wash my eyeshadow brushes maybe once a month. On the rare occasions I use eyeliner I wash that brush immediately after.
Eta: I use diluted baby shampoo. I figure that if it's gentle enough for my eyes it's gentle enough for makeup brushes.
Pretty often- every week or every other week. I use the Beauty Blender solid cleaner for my blender, but I usually just use my face wash for my other brushes because it's cheaper.
I got this brush egg from Amazon for $5 and it's a life changer for me. It makes it super easy and fast.
This is interesting.
I have the Sigma brush cleaning glove and love it. I don't know why this seems more attractive and convenient to me, but it does.
I will say -- I love that the sigma glove has two sides and a number of textures. I do use them all depending on the brush and what it's used for.
I really need to wash my eye brushes more often. I wear MAC Fluidline and once my angled brush gets gooped up, it's that much harder to draw a smooth line. I think I'm going to get that brush egg - thanks grace!