>>7921573There aren't a lot of complicated techniques in the picture you posted; most of the buildings are just basic plates.
What makes it look nice is that the builder has a good eye for proportion, scale, and detail. These are all things that you get better at by making your own buildings.
For example, when I first started making buildings, I put the wall pieces directly on the baseplate. Later on, when I started looking at real-world buildings, I realized that most buildings had a foundation underneath the actual wall. Now I always make sure to put a foundation that's one or two bricks tall at the bases of most buildings. It makes them instantly look more realistic, even if the building itself is just stacks of basic bricks.