Paul Klee produced a number of "Pedagogical Sketchbooks" during his tenure as faculty at the Bauhaus school. In them, he explores some of the basic principles of design as we are in this course. Looking for instance at how he explores the character of line would be useful for the current project.
You can view a PDF of a book of his notation here:
http://ing.univaq.it/continenza/Corso%20di%20Disegno%20dell'Architettura%202/TESTI%20D'AUTORE/Paul-klee-Pedagogical-Sketchbook.pdf
