To do this, once the new setting is mapped out, one uses the background cards. These are a set of 27 cards with a single sentence on each. The say things like "Piracy Flourishes in This Space" or "This Species is Barred from That Space", or "This Species Runs the Central Station." Some of them are in gray letters on a white background and are meant for Oxygen breathing species. The rest are in white letters on a cray background and meant for Methane breathers.
The cards are shuffled, and four are dealt out to each species territory. The players and GM go around the table four times, laying out a card and determining what species is meant, and everything is recorded, so instead of saying "This Species is Barred from That Space", they would say "The Kantuan are Barred from Stoshi Space!"
There are three cards that probably should always be in the number dealt out, but actually, it really doesn't matter all that much. Things can be worked around. In any case, this gives a setting with odd places, prohibitions, and quirks.