TLDR Summary
- Modern buildings are rectangular, smooth textured and ... boring
- Buildings need to contain a variety of shapes like circles, triangles as well as rectangles.
- Buildings need to have interesting textures and details.
Modern cities are filled with dreary and boring buildings. As a result our cities are not really places that people get attached to. So I have developed a couple of rules that are basic to at least giving a building a chance of being nice to look at.
Rule #1: Use a Balance of Geometric Shapes
There is an idea in architecture that a good looking and interesting building needs to have a balance of the basic geometric shapes within it. This means that there should be in any building circles, triangles as well as squares or rectangles.

Honestly I think most of architecture school could probably be boiled down into one 15 minute class which goes like this: "Squares and rectangles, use them. Use lots of them. You can't go wrong with the good ol' rectangle. Here's your diploma." (end sarcasm).
Occasionally one will see the odd circle or triangle thrown and god forbid an oval, a hexagon or an octagon. Unfortunately they are typically lost among the vast number of square and rectangular shapes that dominate our cities. When it finally comes time to demolish these buildings there will be no one protesting to preserve them and their historical significance. More likely the dominant emotion will be: 'good riddance'.
Rule #2 Fractal Textures

A fractal, in layman's term is something that looks self-similar at any scale you are looking at. A good example is a coastline. From space, a coastline like Norway's has a certain craggy look to it. Get closer, say in an airplane at 30,000 feet and that coastline is going to have a similar craggy look to it. Get closer, say a bird's eye-view of a hundred feet or so and the coastline will still have that same craggy look to it.

Thank you for reading. Have a nice day.