How do painters do this

 Tried my hand at the "a la prima" technique again. No sketch, no reference, just going in with a paintbrush. I think I need a size pressure along with a fixed rotation mechanic, where I just paint in a direction and it rotates the brush to that orientation, and it keeps it there until I let go.

 Overall, I think there's something to gain (or at least learn) something from this technique. I think it's worth it if you plan on doing a painting without lines anyways, saves you from having to do lines anyways since you're just going to have edges. Maybe I can integrate it with a line-art based approach too, but we'll see.