I'm trying to keep my sketching fresh by testing some different styles. For this one I tried to be really shaky on the hand. My oppinion is that the best benefits from this technique is that you get away from trying to make perfect lines, so it doesn't take to much focus. I also think that it's easier to experiment with form and to get a nice sketchy feeling, but as always I think the best is to be able to combine and switch between different styles when sketching in a project, because different styles helps you find different forms. Especially when you get stuck in a project it's very good to both work with different sketching styles and different sketching material, like different pens, analoge/digital...
I'm guessing that this technique suits quite well when you scan a sketch and render it in Photoshop. I might try to do that with the screwdriver to the right when I get time.
Equipment: Black ballpoint pen
Time: 2-10 min per sketch