Horizon Forbidden West

• Some items in the Junk category are useful. Pristine Skulls can be traded for other animal bones. And as of the DLC at least one Apex Heart type is used in an upgrade recipe.

• If you want to upgrade something, just create a job for it whenever you're at a workbench and it'll automatically show you where to find the nearest components that you need.

• A few areas will be inaccessible to you at first and will only become available after certain plot-related upgrades, so it does help to progress the story.

• Purgewater disables many elemental attacks and also reduces a machine's resistance to elemental attacks.

• Many sidequests offer good weapons and armor this time around, so it does also help to complete them as they appear.

• You're invincible while performing a Valor Surge and so can also use it to escape explosions, machine charges, and environmental damage.

• Unlike Zero Dawn, the game world persists after completing the main story, so there's nothing that can be permanently missed.

• If a weapon looks at all interesting, just grab it! Weapons are cheap, and most have a unique combination of ammo types.

• Green weapons stay relevant much longer than in Horizon Zero Dawn, and blue weapons can remain situationally useful the whole game.

• You only need to get within 40 steps of a campfire to unlock it for fast travel (i.e. you don't actually need to go up to it and use it), so sometimes it's worth making a detour during exploration to unlock a campfire for future use.