There was also digitally created drawings on photoshop etc, before any anything was created to help develop a better idea of the outcome. I also found these really amazing and how they really do translate from this to the real thing in the films.

I went to Harry Potter studio tour a few weeks ago and the art and design section was amazing; I love these drawing designs of some of the sets and pieces created, they are of such a good quality and it is so interesting to see how they pieced things together.