Taking one of my earlier drawings of the castle as an example, I went on to make a SketchUp model of it, in order to see what it would look like from different angles. I am still experimenting with certain aspects of it. I will probably develop it further later.
Here is the initial result. The model is a simplified version of the castle as, at this stage, I was hoping to research the overall shapes and layout of the building rather than the details.