One essential is hinging. There are many tools available, for at least 3 different types of hinges. There are CA hinges, Robart style pin hinges, and the flat plastic or metal hinges that come with joining pins (there's even a plastic version that joins the two halves with plastic, so they're one-piece hinges.)

I suggest you choose your method, and look at the available tools. Perhaps hinge some dummy parts before working on your prized model. That would be time & money well spent.