I start with a bus leaving enough headroom for multiple stations in the top part and a mall close by.

After trains, first I bring ores and then I start building minifactories for dedicated production drifting away from main bus.

When bots are available I start by converting the mall and then the main base is turn more or less into city blocks, but keeping the main bus.

Not as extreme as this but you can get the idea.

Fot the moment, it has worked everytime (including K2, let's see how it goes with current run of B&A) and the main plus (IMHO) is that I don't end up with a base that looks the same every run.