A few things I thought of:

-Bears, please taunt. If you have more armor than your teammates, they need you to take the damage - to tank for them.
- that goes along with mages healing, mages please heal whenever you can
-Also everyone else, don't rely on mages to heal you. Heal has a cooldown and is not always enough to keep you alive, you need to use your health pots as well
- don't get mad if somebody else gets a good drop. Just tell them "Grats". If it's something you want you can offer to buy. Everyone gets their own roll for drops, so it is nobodies fault that you didn't get a good drop. It's just luck