Every healer needs to have this macro binded:
/ac <heal_skill> <tt>
so you can remain targeting the boss / mob while seeing your own aggro order on that mob yet still able to heal the target that the mob targets
A <- you got aggro
2 <- you are next in line, watch the meter
3 <- you are ok just don't get crazy
4 <- what the heck have you been doing
besides from looking at the name color of the mob, you have to select the mob to see the threat level you have on it compared to your party member
