No Man's Sky - General Settlement Tips

Tips to Settlements

If you found the settlement because you have it marked from space – Another player owns that settlement, that’s why it’s on your world map. It’s marking a “safe” location to ship hunt, use the trade terminal, maybe see if they’ve installed a few refiners…
If you found the settlement because you used one of the settlement maps (which you purchase for 5 navigation data from the navigator NPC on the space station), then that settlement is usually marked as Available (Sometimes this gets screwy in high traffic areas, like Expedition routes, and it marks already claimed ones, YMMV).
You may only have one settlement active at a time. If you pick a new one, you automatically abandon the old.

You get a free one as part of the old 3 hrs/5 warps cycle for freighters. The distress signal usually occurs in between accepting/rejecting the first freighter and the next cycle of freighter rescue. After you’ve founded that first settlement, you can swap to a new one with a settlement map later on.

Or you could just buy a settlement map and try to jump start the whole process before you mess with freighters. I believe subsequent settlements do cost to take over, but as I was at the unit cap at the time I didn’t notice how much it was. When you’ve got 4 billion units, any purchase is kind of a drop in the bucket.

It’s passive income, some NPC interaction, but mostly its a free platform to build on by moving a base computer next to it. (Most of the infrastructure parts are already built in the settlement, so you’re only adding refiners, or special features to the base).

General Tips

Save often: update your Restore Point by exiting the starship, claiming a Base Computer, interacting with a Save Point/Save Beacon, or the waypoint machines you find at some Points of Interest (POIs).
Sentinels are like police in NMS: they don’t like it when you destroy, mine or harvest rocks or plants from a planet. When they’re watching, stop or move away from them to resume harvesting resources. Avoid entering your ship with an active Sentinel Alert Level: sentinel ships are more difficult to evade than planet sentinels.

The Space Anomaly NPCs and terminals are the single biggest source to learn technology or base part blueprints.
To easily return to a system or planet you like, place a base computer and name it something you will remember.
Storage upgrades can be applied to exosuit, ships, multi-tools and freighter. To apply a storage upgrade to a different inventory, switch inventory by pressing Q or E (dpad left or right), then apply the storage upgrade. Storage upgrades can be purchased with units, but also obtained from other sources like scrapping ships or mission board rewards.
Discovering and registering the complete list of fauna on a planet (at once) will reward nanites – 250 per fauna.

Planetary Settlements

Intro to Settlements:

Introduced via the secondary quest, A Planet in Distress.
They start off small and modest, with a sparse population and only a few buildings scattered around their town centre.
You can only have one (1) at any one time. Becoming Overseer of a different settlement resets all progress from the previous one.
You can find another settlement on another planet you prefer by using Settlement Planetary Charts (bought from Space Station Cartographers, 5 Navigation Data each).
Settlements can spawn on most planets in inhabited systems.
If needed, save before using a chart and reload the save to reuse the same chart.

Settlements Upgrade Over Time:

A new Overseer decision is generated 15mins to 2hrs (real-time) after the last one.
Maintenance Cost and Debt do not come out of your Units balance, and you cannot buy off settlement debt.
If Debt = 0, productive settlements generate products and substances. See products breakdown:

While a settlement isn’t a huge money maker, it does have two (2) production output slots. Over time, the Trade Commodity slot upgrades to a higher value product as the settlement progresses, while the other is fixed and depends on system race.
Out of all the settlement stats, Population is the most important. During Overseer decisions, allowing Settler Expeditions often results in population loss.
Reaching A-class is fairly easy and doesn’t take a lot of time investment. On the other hand, S-class is nearly impossible — among its requirements: 200 population, 1M productivity, 100% happiness, 0 debt, 0 maintenance.

Sentinel Attacks:

Settlement activity draws attention from ground sentinels. When the sentinel alert level has reached 100%, the settlement is attacked by corrupted sentinels.
If the settlement is under attack but the alert level has not reached 100%, the attack is most likely due to the secondary quest, A Trace of Metal. Finish that stage of the quest to stop the attack.
Being in a multiplayer group may prevent the settlement owner from ending an attack. If that’s the case, leave the group, save, and reload.

I sincerely hope this was helpful. Good luck to you!