How do you arrange your figures?

I've got a quickly growing collection of marvek minifigures and while some will be used to set scenes within my city, I'll still have a bunch left over. I've been printing stadium-like stands that hold 13 figs each on 9 different levels, but I'm having trouble deciding how to arrange the figures. My first instinct was all the variations of the same character together but visually most just blur together and its not very striking. Anyone have any systems they use or ideas or are just going...