Working off of this list because it sounds like a good way to put a loose, anti-canon setting together. (Anti-canon is definitely something I'm aiming for for Liminal Void so I'm game.)
Step 1
(mostly a repost from here so it's in a useful place, made slight changes here and there)
Inspirations
The Expanse
Cowboy Bebop
System Shock
Alien/s
FTL
About
If I had to narrow it down to statements would probably come out to something like:
Space is inherently hazardous and by all rights nobody should be in it. This is more true the less populated the area is.
The farther out a station or colony is from any of the centers of corporate power, the more exploited and extracted they are, but the easier it is to achieve some kind of independence.
Being thrust suddenly onto the fringes of society and having to figure out how to deal with that.
The wildly disruptive nature of independent ship ownership.
Step 2a: Icons for "Space Is Inherently Hazardous"
Event: August 6th (Terran years, because most of the foundational software libraries that govern time were written centuries ago and nobody's willing to rewrite them) is celebrated galaxy-wide as the anniversary of the first successful wormhole transit between Earth and Mars. The unsuccessful attempts don't get holidays.
Landmark: Vulcan Station, the first permanent space station orbiting the sun opposite Mars, is somehow still technically intact a century later. The inside is still highly irradiated thanks to insufficient turn-of-the-century containment tech, but its wormhole beacon is still active, so its outer docks are still occasionally used for resupply/refuel efforts.
Person: Every wormhole beacon placed is the result of someone traveling for years on end to place it. The most famous one goes by Trailblazer. Their trips took longer and longer, and every time they returned they looked more haggard, telling tales of how absolutely empty space gets. They embarked for Pluto, and they haven't been seen since.
Peril: Someone decided years ago that they wanted to try to breed vacuum-survivable beetles, allegedly as part of an effort to try to seed "dead" planets with an ecosystem. What it accomplished is that every once in awhile, a far station will get absolutely infested by a few stowaways in a poorly-checked freighter hold.
Treasure: An absolutely delusional billionaire set out on a long-term freeze colony ship nearly two centuries ago, long before the highest-thrust drives were developed and any beacons were set. They were aiming for Mars, but they never got there - from what we now know, their reactor probably failed about halfway there. Allegedly he packed all kinds of fineries on his vessel, though...if someone were to find it they'd be worth a fortune on the antiques market.
Secret: Some ships head out for a beacon and just never get there. That's at least partially because the corporation who runs the primary wormhole network can interdict travel for ships of interest and redirect them to a secure beacon of their choosing. But in truth, not all of it's being done by them, and that terrifies them. Where are the rest going?