Forget a gym membership. All I need are weekends spent in the yard turning compost; my goodness am I sore. Last summer I built a four bin system out of 12 scavenged pallets, L-brackets, and some hooks and eyes. I researched plenty of building plans online, but ended up just winging it once I started putting it together. Some people get fancy and include hinges so the front "doors" swing open. Not me; I kept it simple. I just started screwing pallets together until I had the backs and sides for all the bins. The fronts I attached using hooks and eyes. This keeps them all together, but I can take off the front of each individual bin when it comes time to get in there and turn.