Watch yourself = roughly 33% dmg reduction if you're a warrior. Couple with dolyak signet and sentinels armor and you should be taking 0 damage from just about everything.
You can throw in physical and elemental resistance if you want.
Stances are good, but they only provide defence versus physical and projectile attacks.
Phys/Ele Res - Bad unless if you know what your up against.
Dolyak Signet is a must have, Gladiator's Defence/Shove is useful as well, along with Shield Stance. Also None Shall Pass is a good choice, and bring a Healing Signet incase your Monk suxorz.
Rangers have some nice stances, and troll ungeunt- good for healing. I don't know if you like to have monk secondary or have only warrior skills though.