As has been said previously while re learning the ropes over power is your best friend. Use it a couple times during the initial pull then throw one in for good measure every couple combos. Watch the mob for who the dps target aswell. You then get a better idea of where you would want to put more enmity.

Just keep playing the role and you'll slowly learn the finer points to the job. Make use of overhealing yourself aswell. It makes for really strong enmity generation when it starts to dwindle.