Crafting and trading are two of the most important elements of surviving in Horizon Zero Dawn. Throughout your journey you will want to collect the various materials you need to increase the potency of your equipment. With this, you may be wondering where to find certain goods when you need them.
Below is a brief list of where to find every type of material.
Bone and Skin
These assembly come as rare drops from hunting animals. Due to their rarity, it is recommended that you are constantly hunting when you see wildlife nearby.
There is a Crystal Braiding type for each of the five different mini-bosses you can kill. When you need a Braiding of a certain type, simply look for its symbol on the map before killing it. If you're successful, you'll walk away with the Braiding. The various mini-boss types are Behemoth, Deathbringer, Rockbreaker, Stormbird, and Thunderjaw.
Glass only drops from humans. The best place to find groups of humans are at bandit camps, so pay attention when you find camps so you know where to go when you need to farm Glass.
Unlike most other materials these are not specific to a certain enemy type. Instead you can find these on Corruptors, Fire Bellowbacks, Freeze Bellowbacks, Longlegs, Sawtooths, ShellWalkers, Tramplers, Ravagers, Snapmaws, and Stalkers.
Machine Core (Medium)
Exactly like Luminous Braidings, these are found on Corruptors, Fire Bellowbacks, Freeze Bellowbacks, Longlegs, Sawtooths, ShellWalkers, Tramplers, Ravagers, Snapmaws, and Stalkers.
Machine Core (Large)
These are found on the same enemies as Crystal braiding's. The various enemy types are Behemoth, Deathbringer, Rockbreaker, Stormbird, and Thunderjaw.
The source of these Hearts is specific to each enemy type. They are a rare drop very similar to bone and skin, only they dropped from enemies that will defend themselves unlike animals.
Just like desert glass these are found on humans as a rare drop. Simply farm bandit camps to give yourself the best chance of finding these.