[SiC]

Let me add some more to what Cedric-Archaon posted.
If you dont have money to make or buy drinks always have a bard and or red mage in the party to help you recover your MP. Always eat food that increases your defense and or VIT. Always use sub WAR and provoke every 30 seconds. If some how the target is away from you and is towards the ranger or some other attacker, cure the ranger with high healing spells to create alot of hate towards yourself. Healing the person that is being targeted at that time will create alot of hate towards you. Always use Defender (when you are level 50 and above) and never use berserk.
Always keep in mind that you are not an attacker but you are the shield of the party. If the party's shield is faulty, the whole party will crumble.

Good Luck!