Take the powder up with the brush and knock off any excess powder onto your hand before applying the powder to the face.

Cleaning
Artificial-hair Powder Rouge Brushes can be cleaned with shampoo or soap and water. For extra hygienic cleaning: Finally, apply Grimas Hygienic Gel to the bristles and massage it well, so that it also ends up on the inner bristles.
Then knock/shake the water off and lay horizontally on a tea-towel to dry. Do not leave the brush upright, because the water will then be absorbed into the shaft.