Just keep up accension stoneskin, accension phalanx, accension regen 2 and rest whenever you can.
If none of your DDs are /nin, then I would replace regen II with blink in my accession cycle, and simply cast regen II as needed. We're so used to blink being an lol spell a lot of people forget about it. With phalanx and pro 4 the average xp mob will hit a DD for around 150, so blink saves 300 hp per. Assuming the mob doesn't have AoEs, then it's way less efficient.
but to be honest if even 2 people get full use out of their skins it's worth casting
^This. Don't be afraid of the no effect message. Once the 2nd persons skin goes down cast it again then regen II the damage, and get a tick or two of rest in if you can.
Also, I know a lot of people say enfeebles aren't worth it if the mob dies in 30 seconds, I say whatever saves mp is worth it.
Paralyze for instance, it's 5 or 6 mp (can't remember) and casts in less than 3 seconds. There is really no reason not to cast it (I know colibri reflect, but since you know it's coming you should be able to remove it almost immediately).
If it even procs one time, that's 6 mp saving hundreds of hp. Add in a goblin mushpot for +10 mind, and a halfway decent mnd enf. set, and you're almost guaranteed to see at least 1 or 2 procs per mob.
One last thing, the closer your DDs are in damage, the easier it will be. If their hate levels are pretty similar, when one gets their skin broken and takes a little damage, the mob should then turn to the next in line and have to work thru their stoneskin, blink, phalanx.
But if one DD is way ahead in damage, then the AoE buffs lose a lot of their appeal, and you'll be stuck cure bombing him.
75NIN, 75BLM, 75SCH, 75SAM, 64BRD, 41RDM, 37DNC, 37WHM, 37WAR