Also, I have a practice of making only a part of the asset. For example, my steam device has very big pipes and a lot of small elements. So, I created only 1 unique meter of the pipe and then just rotated it. More than that, I took it apart and reused the parts later in the scene.

I think the GDC session from Fallout guys helped me here. They said that they created a big kitbash for a modular environment and used it to build different generators and machines. I did same, but in another way.

And the last thing – I tried to use Epic Games pipeline from Paragon. I did not take any texture assets – instead I assigned material functions and played with tiling. For some assets, simple material can look very cool. Their pipeline is much more logical, but using material functions and blending them with BW mask gave me a pretty nice result. I think I will practice this pipeline much more – you can greatly increase resolution of your textures.