Lines — I've conducted this project in my head numerous times over the years, wanting to start with the most basic of starting points—pencil, blank paper. The prompt was simple: draw lines, on paper, by hand, in black & white, for 100 straight days. Don't worry about "what to draw." Just draw and let the action dictate the result.
Most of these started without a clear goal in mind beyond those parameters, though I did switch around from a variety of markers, pens, pencils, charcoal sticks, brushes, etc. If I stumbled on an approach I liked, I repeated it the next day, resulting in mini-sequences that can be noted below. Alternately, if one day's drawing method was not as successful, I would shift tools the following morning, but the goal stayed the same: to draw for the sake of drawing, without agonizing about the end result. (Entire series can be seen here)