Hello there! I'm working on this piece right here and I really apreciate some tips and critiques! It's my first piece in Unreal and the first modular and external too. The pic represent my attemp into the lighting and composition, later I'll build one more modular kit for buildings and refine stuff.
I do have something that is my key ref for mood and structure which is this paint of Charles euphrasie kuwasseg: https://imgur.com/a/auPHDpw
I changed the hue a bit to experiment with the mood and also related some props (the images are in the same link above). For the buildings in general, I'm working in an additional modular kit to match something like 16th century architecture. I'll post newer images soon.
In your roof texture for example, the roof tiles are huge.
As is, the modeling looks very lowpoly - is this intended?
Maybe it would help you to find a reference execution and style wise too, so you have something to check your quality against and to extract some techniques from.
Generally I would recommend you to keep your scope reasonable (as small as possible in the beginning, it will explode anyway ) so you can complete your project in a reasonable time with good quality.