Cheap Terrain

I have two generic modules made out of Burger King Kid's meal giveaways and a ton of crates made out of soda bottle lids. The only thing better than decent looking terrain is decent looking terrain that was dirt cheap. I don't know who invented the soda lid crates, or maybe there were one of those good ideas that multiple people discovered at once like fire or the atlatl but they are super easy and look good with very little work.