Flash, circle of scorn, flash some more then single target combo what your focusing (kill target), run low on MP use the combo to replenish it. Rinse and repeat

If that doesn't work then re-evaluate your gear. if that is not the case then see who is taking hate and pay attention to what they are doing

IF DPS is not targeting your mob tell them to stawp it and kill your target

IF the WHM is dropping heals on you when your FULL and/or spamming AoE heals (back 2 back) tell them to stop it and l2p

IF your in a party with people who has better gear than you. ask them to let you build hate the mob

Always pay attention to the threat bar

/end