1,001 Symbols: An Illustrated Guide to Imagery and Its Meaning, by Jack Tresidder, that 7th graders could easily access. They were asked to choose the qualities that they valued in themselves, first, and among the assorted symbols, find three that they could picture using together in one composition. They created a thumbnail sketch, using a circle, square, rectangle or shield shaped format.
I permitted the use of one piece of clip art. I have a collection of antique-ee clipart, which is the only kind that we use. I go into a little bit about copyright law, here. Students are so used to taking images from the internet that they don't question whether it is right or wrong until you point it out to them. I introduce a little bit about using the text tool in Photoshop here, if the students want the lettering to curve..