I would say it depends on the type of city you are building. Currently I am building a city that is inspired by many midwestern cities, and Las Vegas, so my layout is going to be a grid. In fact most American cities are on a grid layout.
Now, while you’re worried about the city being “symmetrical and blocky” that is sorta the name of the game regarding a city. A great reference in city planning would be the youtube channel City Beautiful, which is a city planning enthusiast who loves to go through and detail city styles. Some suggestions I have to make it feel less “blocky” would be to have roads which are at a different angle, or have a radius. Furthermore, you can use big landmarks such as a highway to break things up too.
As for making the city feel bigger, make the roads narrower, the actual city may be small, but buildings will be closer to each other, creating that city feel.
I also agree with using textures, and that is what I do personally.
As for planning, I like to break my city into sections and build out a few blocks, but also keep in mind generally what will be adjacent to those.
Layout of my city so far, I also included a link if you wanna check it out.