Like I said World building was/is my thing, and here is an example. Following a lot from Gregory S. Paul's "Redatory Dinosaurs of The World" and a little from  iisaw, I produced an écorché drawing in colored pencil to work out how the muscles worked, and their general anatomy. I used to do a fair amount of work on colored pencil, but that is something else that Photoshop made somewhat irrelevant these days. Pencil on paper R U G G E L S