These simple little cartoons that people scribble while they’re chatting on the phone or listening to someone boring can also really improve a person’s drawing skills. Just a few strokes—a rainbow arc, a wavy line, a small cone for a stem—make an acorn appear on the page. Complete the picture by giving it a smiley face and a “speech balloon” with some witty words inside. It’s just a short jump from a single picture to a full-fledged comic strip.