What can I make a baking form from?

I'm looking for a way to make a precise form for baking bread in it. I have a gas-powered oven at home and I'd like to find an easy to shape material that could be used to make a complex form or parts of it that can be assembled and will not deform from heat or the pressure of dough. I don't think I can manage precisely shaping something as hard as metal pans, but perhaps wooded planks with some preparation could work?