Focus target the dps that's pulling your hate. (Shift +f)
Use focus target to see which enemy is that particular dps's main target and focus combos on that one, flash on others.
Use the enmity / threat bars of specific enemies to gauge how close you are to loosing agro. Adjust skills accordingly.
When possible start your fights with the skill fight or flight.

It's not that hard once you get the hang of it!