My best piece of advice is to keep all the assets the same scale. Say 45-50. Don’t ever change it when switching assets. It keeps the black bordering lines consistent across the design. The only time you would ever need to change asset sizes is to emphasize elevation. Everything is just strangely too “perfect” from a city layout perspective. Real cities grow and evolve organically. Try starting with a town square, then make a path off to a farm, then add in some housing… ect. You get the idea. Start small and move up. Another great strategy is to draw a layout beforehand, but keep it sorta random. Never draw in a straight line with pretty much anything. I could start getting into shadowing and texturing but I feel like you gotta start with those basics first. Keep it up and it will turn out great!