A brush that I made for blocking and blending. Has its own unique texture made from perlin noise and opacity properties I customised myself.
Not the only brush I use, but one of the main brushes I use. I use it mostly for, well, blocking and blending. Usually to block in shapes and colours/values, then I go over it with another brush to render.
But the shape of the brush and the texture of the brush makes it very pleasing to block with and to blend colours together without making it too "smooth" looking. I decided it was about time I stopped putting off sharing this brush so that other people don't have to customise their own marker/paint-on-rough-texture brushes LOL