The weapon crafting in Horizon Forbidden West really adds a layer of depth to the gameplay! You'll want to focus on gathering specific materials like Metal Shards and various animal parts, since they're crucial for upgrading your weapons. Prioritizing rare resources like the parts from Thunderjaw and other tougher machines can really boost your damage output.
One strategy I found helpful is to always keep an eye on your inventory after battles. Make sure to dismantle any weapons or equipment you don't use as they often yield valuable crafting materials. Are you leaning towards a particular weapon type, like bows or slings?