Here are a few a build rules I developed between 2.0, CivTemp, and 3.0.

I've implemented them and they've proven to be minimal in terms of red tape and simple for newfriends and citizens to follow:

Suggested Rules for Newfriends & Citizens

• Build next to an existing build

  • If your goal is to build a town or city, instead of a village or hamlet, this rule can help make your town feel dense without requiring a large population

• Leave no space between your build and your neighbour's. Take a look at this to learn more.

  • Making full use of a plot or space that you've cordoned off is important for a variety of reasons, but at its core it gives you a fine lookin' street. Take a look at Volterra, Breslau in Civcraft 2.0, and Alexandria in 3.0

• Use a minimum of 3 different materials for your build.

  • This rule is just to prevent single material shitboxes.

Suggested Rules for City Planners

• Try not to flatten or cut through land when building roads

  • The variation in road layout that's added by moving along the contours of the land is an easy way to make your town look distinct.
  • Viridian inside the walls looked like crap because of The Flattening. Viridian outside the walls on the other hand, in the Venice district, looked great ^{because I made the initial roads and layout with this rule in mind.}

• Don't do Orion nor Viridian-style grids

  • Grids can be fine, but Orion-style grids that result in individual builds that are each surrounded by roads generally look awful. If you want to do grids, take a look at how existing cities IRL do them and implement the aforementioned build rules to make sure that your gridded city also has an aesthetically pleasing streetscape.

You can tweak the rules as much as you'd like, but at their barest this is what they come down to.

I think with civ servers, many towns end up going for the standard plots and road layouts, which in the absence of a skyline can make a city seem like your run of the mill cookie-cutter suburbia.

I do understand why it happens. There's an assumption that a good looking city can only happen with a good bit of central planning, and that can get in the way of the innovative spirit of cities that value individual liberty and freedom. In many instances, there ends up being a tradeoff between industriousness and a well designed city.

The rules above can quell that. You can build streets however you like, but as long as the above rules are generally followed by newfriends and citizens, you should end up with interesting and aesthetically pleasing streetscapes.