Web site Light Doodles teaches you how to draw in a photograph using light. What the heck's a light doodle? See an example in the included image, and hit the site for a video of how that was drawn.

Christopher Wilmarth, “Half Open Drawing” (1971), etched glass and steel cable, 24 x 17 1⁄2 x 1 inches (Dallas Price and Bob Van Breda, all images courtesy Craig F. Starr Gallery, New York) ...