If you don't mind, I'd like to add something: Order your party list by healing priority. In other words: Have tanks on top, other healer either on bottom or near tanks. This makes it quicker to change targets, and also allow you to always know the position of your tank. My prefered pt list setup is something like

Me
OT
MT -> main target.
Healer
Ranged DPS
Melee
Melee
Ranged DPS 2
Fairy

As this allows me to switch to some of the highter priorty targets easily:

MT? Heal, is the main target.
OT? Up, heal
Me? circle (cancel targetting), heal
Other healer? down, heal

and so on.

Reduce the number of targets you have to cycle up so the higher priority ones are 1-2 button presses always.