In my webtravels, I stumbled across a link to this
instructional comic: http://kalidraws.tumblr.com/post/32953413185/today-i-gave-my-students-a-quick-presentation-on.
Essentially, it’s a short slide show dealing with positioning, shapes and lines, cropping, and proportions, with quick-sketch illustrations of each point. It’s designed for drawing, not photography, but I think a number of the rules apply, so you might find it useful in thinking about your street photography, collage projects, and maybe even Snapshot Day, which is Thursday 10/11. I’d love to hear your thoughts!