I've been up and down this website for the past week totally geeking out about how applicable it is to environment artists. I highly suggest you take a look through it and study how things are constructed, and what parts he uses. Looking through this, at the casts and the instructions, it opens my mind to what pieces I need to make for an environment, how to split them up for maximum usability, and how to construct a full scene using the pieces I make.
You may recall when I made a plaster environment a few years ago and how much I learned from doing that. I highly suggest this activity to anyone, as the insight you can gain from doing this you can't get anywhere else.
I'd love to hear your thoughts, and if you have more resources like this then post them up!