Xenosaga Episode III: Also Sprach Zarathustra Tips

Gameplay Tips
Equip gear to display data:
It is important to have one character and E.S. with an accesory that allows you to see the enemies' physical/elemental weaknesses and strengths. If you're not aware of these properties, you may waste a special attack, an ether attack or a tech attack only to see it land 0 damage or even heal the enemy.

Kill enemies with your special attacks:
This is a must if you want to have a strong party,
landing a finishing blow with your special attack will net you an extra 50% in experience, skill points, and gold per enemy. Using traps to fill an extra boost gauge before normal battles will help you finishing the battle with special attacks. And in boss battles, where I really really recommend you to land a finish strike, when you see that he doesn't have much HP left, you should use analyze to see the remaining HP of the boss and know when to use a special attack to finish him. Doing this will assure you to have a stronger party.