Dumpster diving is my favorite! *eyeroll* If you time it right, you can peek in dumpsters around colleges right after the semester lets out (more so for summer break) and find some nice furniture and storage stuff. It's normally not icky, either!
I know it sounds gross, but I've gotten some nice chairs and storage things that way. I don't pick up anything fabric, and I've seen nice shelving units before (when I didn't need them :grumpy

. With a little cleaning, everything turns out OK
Sorry, my mom taught me how to be super-cheap lol