Logos can be created by combining text, shapes and colors. Have students create logos for their PBL companies / products, to represent a book they have read, an extracurricular club, a character trait, or many other things. Students should have a rationale for the logo. They need to be able to explain their choice of colors, why the shapes were put together the way they are, and and symbolism that exists. A logo shouldn't just be created because it looks cool.