I try to spread mine out equally between characters so no one loses too much MP at one time.

I think they're something like this:

Ally KO: Arise
Ally HP < 70% Renew (when I'm in an area that is way harder than I'm used to xD)
Ally: any: Hasteaga/Shellga/Protectga/Bubble
Foe status Protect: Dispelga (I find the most common annoying buff an enemy has is protect, andi f they have protect, they usually have something else)
Foe HP = 100%: Steal
Undead: Holy (for hard areas, else Curaja)
Foe Ice-weak: Blizzaga (for the necrohol)
Foe= Flying: Telekinesis
Foe= Any: Attack

Nothing very special. I dont' even have all the slots of some characters all filled in. I just add them as I go and if they get annoying I turn them off or replace them.

Ally=any: Phoenix Down will trigger any ally who needs a phoenix down. It's pretty much the same effect.