Scan Everything
When you first start up No Man’s Sky, you’ll find yourself stranded on a mysterious planet with a lot of damaged equipment. That only things that works right away are your Life Support and your Multi-tool. You’ll need to repair your Starship’s various engines and drives in order to not only fly around your current location, but to take to the stars, as well.
This may sound counter-intuitive, but before repairing your ship, you should repair the Scanner component of your Multi-tool. This module does exactly what you’d expect; it scans things in the world (plants, wildlife, and resources). That alone may not sound like much other than a way to gather information, but it’s also a means to gather one of the most important resources in the game: Units (No Man’s Sky’s currency).
Scanning new elements of your environment will add them to the Discoveries tab of your pause menu. You can then upload those discoveries to the Galactic Library and earn money for doing so. The more you scan, the more you earn. With an impossibly large amount of planets to explore, that’s a pretty much endless amount of money you can earn.