Upgrade materials are most valuable when they strengthen a weapon you are actually using. The main early mistake is splitting resources across too many experiments before a favorite has emerged.
1. Pick one main weapon first
Choose the weapon that currently feels the most reliable and spend enough resources to make it keep pace with your progress.
2. Keep experiments cheap
You can still test alternatives, but do not raise every interesting weapon equally. Learn the moveset first, then commit materials after it earns a role.
3. Upgrade when damage is the bottleneck
If you are surviving comfortably but fights take too long, weapon improvement is a strong next step. If you are dying instantly, survivability or positioning may matter more.
4. Reassess when your play style changes
A new weapon only deserves investment if it changes what you can do or fits your preferred approach better than the current option.