If it is still like the old DFO, learning when and how to retreat can be a good thing too: have some big tanks cover the glass canons with huge effect spells. So the enemy hesitates enough to let you get ground.
If you can have reinforcement, retreat to a good fighting ground (high, with cover on top but nothing on bottom) and stall the other force enough for the reinforcement to get to you. Focus on healing and doing flashy spells to impress. If possible, focus fire one target or two to down them so they lose time reviving and think again about attacking.

If this is not possible, a full retreat should be made with small 2 men groups in every direction but the ennemy's. Then groups which are followed by 1 or 2 guys can join other free ones to ambush the fuckers and destroy all their stray.

Also one thing Donk forgot: consider dieing as a learning experience, not defeat. Don't go out with gear you're not willing to lose.

[Linked Image from w3.the-kgb.com][Linked Image from w3.the-kgb.com]