Mapping a Settlement
Step 1. Layout: The layout of a settlement is as unique as the terrain upon which it's settled. In settlements developed before the advent of spaceflight, you might want to look at major trade routes likely developed alongside rivers. In more modern cities, this usually means looking at where the city's spaceport is located, likely near a body of water for emergency landings or where land would be cheap after the advent of spaceflight. The settlement might also use a structure like a space elevator, which likely makes its anchor a solid hub. If your settlement is a space station, build the central core and expand outward.
Step 2. Districts: Archaic settlements likely have a central district once defended by a wall. In some settlements, this area might be the most expensive part of town, filled with palaces and tourist districts, allowing guests a look at years gone by. If the settlement was established during or after an industrial revolution, the old town might very well be a run-down and polluted den of criminal activity. Districts often naturally develop as settlements grow into adjacent settlements, incorporating the smaller town or village into the larger settlement. These different wards often specialize over time into the dominant industry of the settlement, with residential districts typically replacing agrarian plots in postscarcity societies.
Step 3. Malls and Markets: Designate one or more open spaces in the settlement as a major commercial space. This marketplace typically grows in the city's downtown, often on the ground floor of office buildings or in large shopping malls. Mid-sized cities often develop these hearts of commerce in marketplaces and bazaars sometimes thousands of years old, using temporary stalls for local food and small businesses alongside large interstellar corporations in newly opened strip malls. This setup gives adventurers the flexibility to buy and deal in exotic and ill-gotten gains while still being able to reliably purchase mass-produced equipment from major manufacturers.
Step 4. Lodging: Heroes need a place to celebrate and recover between adventures. Bars, clubs, and restaurants make ideal locations to rest, introduce notable NPCs, and initiate quests. Unlike the medieval tavern, the hottest locations rarely have lodgings of their own but are often in districts featuring hotels or close enough to the spaceport that you can always save some credits bunking in the party's starship. Some cities feature alternative lodgings, ranging from sleeping pods and overnight cyber cafes to hostels and house rentals.
Step 5. Landmarks: To give your cities a sense of personality and local flavor, design a handful of iconic landmarks for the PCs to visit. Memorable names make these landmarks more interesting and can help hint toward future themes and story beats. A random stellar observatory might be noteworthy, but the Tapestry's Eye has an air of intrigue that could lead to a fun adventure hook.