To anyone but me those scribbles mean little, as I can't draw for love nor money! So I created a proper mock up of my idea. I knew, of course, it might not end up exactly like this, but you start with something you ideally want then you are guided as to what's possible. So I created my mock up, noting some reasons as to why I wanted things to look a certain way.
One of the main considerations for me was texture. I wanted the mix of suede, leather and metal to be prominent