To solve that I invested in four magazine organizers and labeled them according to the four things I most need to organize: Grade, File, Copy, Hand Out
This covers most items that I encounter during the day. I had the same system last year, except I allotted myself horizontal bins, and the problem was that I could stack papers until they were nine inches high and it wouldn't be a problem.
(you can also get a glimpse into my ridiculous sharpie obsession... I know, I have a problem)
In order to curb my desire to keep stacking piles (particularly the "File" one) I got these very space-limiting magazine holders. I know once that particular sorter is full I must do something with the contents, so it forces me to keep on top of whatever it is intended for.
They were plain (and boring) black, but zebra duct tape to the rescue! I added labels in the form of my little black paw prints, and viola!