I got 3 free pallets somewhere, and used those as the bottoms of a 3-bin system. Then I took some leftover wire fencing (freecycle is a good resource for this sort of thing)and 8 of those metal fenceposts, and made 3 bins that share walls. In one bin, I dump all our mulched autumn leaves, in the other goes grass clippings and in the middle one goes everything we have to compost, using the green or brown stuff from the outside bins as needed. If one of thsoe is empty (sometimes I keep the grass clippings in a pile next to the compost heap, so that I can turn the heap from one bin to the next, aerating it and making it "cook" faster.
Hope that helps. It was really cheap and easy, and I made a lid too with the fencing to keep the racoon out.