i just bought this contouring brush. am excited as i never had a dedicated contouring brush before.
All i had were angled blush brush which i double up.
see video on how to use it, gives you the very nice contouring brown lines under your cheekbones https://youtu.be/qVnofUu8_L0
There is a previous thread somewhere about contouring and highlighting.
The brush is used to apply the contouring or highlighting powder to the appropriate places. It’s used pretty much the same way as a brush for applying any other powder such as blush or eyeshadow.