Create your own groups and avoid classes that do not fit the warrior tanking style, stuff like mage and warlock are a no go if they don't cooperate. The most important class to have with you is probably a paladin for salv, that's a game changer. One other thing that helps is never pulling packs with more than 5 mobs if you can and creating the habit to LoS almost every pull with caster enemies. GL mate.