How to model how to add real-life pictures and rookie-level ps to make the door head renderings, the more detailed the better.

Draw a sketch first, so that you have a good idea, otherwise you can't proceed. Set the size and resolution. Then draw auxiliary lines, set the vanishing point of perspective, one point perspective, or two points perspective, and then make auxiliary lines. After drawing, start to tick lines and slowly fill in colors. Never mind the details, but have a big effect. When you are finished, make details and add shadows. Insert real scenes, background blueprints, trees and lawns, etc.