From CreativePro.com –CreativePro Tip of the Week: Drawing Instant Abstract Art in Illustrator:
Did you know the tilde key has magical powers in Adobe Illustrator? Yes, the humble, unassuming tilde key that sits near the top left of your keyboard. By pressing and holding it as you drag with any of Illustrator’s shape tools, you can draw instant abstract art. When the tilde key is pressed, Illustrator creates a new shape each time the screen redraws. So if you move your mouse or pen tablet slowly, you get a lot of densely packed shapes. If you move it faster, you get fewer shapes spaced farther apart. The results look a little bit like an old school Spirograph (if you’re a child of the 70s-80s). Experiment with different strokes and different starting shapes, like polygons and stars…