Using circles as a repeating element throughout the yearbook. You could use school colors, color scheme colors. Solid circles and rings. Play with transparency of the circles too. Another Cirle Brochure by Tony Huynh, via Behance
I don't think this is TOC but I like the diamond/triangle shapes that are used to cut out various photos. The collage effect works nicely with the nature scenes in the photos. The center diamond with the copy reminds me of a compass.