Subnautica Game Mechanics Tips
These are some things I wish I knew when I started. They're mostly about game mechanics that were non-obvious to me.
Check your Radio every now and again
Messages will arrive once it's repaired (triggered by time passing or actions you take), and they not only add to the flavor of the story and world, but they will often point you in useful directions to find new resources and story related stuff.
Explore Everywhere, Scan Everything, Build Everything