Test renders

I have used Photoshop a lot of times to blend an Ambient Occlusion render together with the original to see how the small details look like. This is to get a glimpse of the final affect all the little cracks, nudges etc. have on the image.
Also, PS was used to adjust colors and lighting as well with the help of tools like Curves so I can get quick results right in Photoshop without rendering in 3D.

Slowly, I start adding color here and there, being very careful at this point. I want to get a good foundation upon which I build the rest of the textures. My aim is to shade the main gate structures and the building on the right, because those are the biggest objects in the scene. The shading of those will drive the shades of other elements, so I have paid extra attention here.

This is an early test render of those textures applied:

Here are some of the assets that populate the scene: