Creating space for clothes, roommates, frat house?

I'm looking for any tips for creating space for clothes and other small items. I just moved into a fraternity house(woo hoo!!) and I am sharing a fairly large room with 2 others. The closet is pretty big but I have like 15 pairs of sneakers, as well as many clothes. What are some good ways to create space for clothes and other things? Any idea on shelves or something?