Ok, I still suck at tutorials! Basically, apply a checker texture to the whole model. Select it peice by peice, add the UVW Map modifier. A planar map will usually suffice, but cylindrical and spherical ones are useful. Unwrap the UVW and move around the vertexes untill the checker pattern on the model looks uniform. If you make each section fill the entire box, then move them out of the way. As you get more and more peices, placing them so they don't overlap is hard, but you can scale them.
Once you've done all of them, it's just a case of arranging them all inside the main box, then using Texporter to make the template.
Does that all make sense?