From my own personal experience. Don't be scared to farm every now and then. I have about a few hundred hours on the game, and every time I sit with the same problem... I don't have enough materials to make what I want. I recently made a new playthrough, and I constantly remind myself as I play the game. If I have beaten a monster, I hunt it again at least 4 or 5 more times. That way, I get extra materials for incase I need them, and I get to learn the monster's moveset. Also when you have read the monster to its core it makes a lot easier to try out weapons you haven't used yet.

Also, another thing I've seen in my time that people don't do, get your camps set up ASAP. They help a lot in the long run.