Hey all,
I've been reading many threads lately about healers, especially holy priests, running OOM in heroic dungeons, so I'd like to share some of my experience of healing through some of the difficult fights. Some of the things I am about to cover have been mentioned by others for countless times, but I hope there is still something new in there.
First of all, something about me: I have been running instances, both normal and heroic, after reaching level 85. Cleared all of the heroic dungeons as a healer except for Throne of Tides (which I haven't discovered for some reason), mostly in guild parties but also in pugs occasionally. Tried a few raids with guild and had no luck except for Barading Hold. Currently sitting at 338 item level, with about 78k mana and 2.4k spirit.
After talking with many other healers in my guild and some random ones on street, it appears that healing in general has become more challenging in Cata, and priests seem to have an even more difficult time than others. For example, an equally-geared Shaman healer in my guild is able to heal through all bosses in Hall of Origination with more than 20% mana remaining by the end of fight, yet I contantly run OOM before the boss dies and have to rely on potions or Druids.
And here are some suggestions for holy priests that are new to Cata:
Know the fights. If you ever want to clear a heroic dungeon without wiping for twenty times, you need to do your homework in advance. Take a look on all bosses' abilities and think about how they are going to affect your party members. Will the boss hit the tank hard? Will he use a large AOE on the whole party? How often does the party take damage? How long is the fight supposed to last? These are all things you need to know. With that information, you will know whether it's safe to leave a DPS at 20% health or you have to top him off. Also you need to tell the party what they need to do/not do for the fight, because there are always people who have no idea what they are getting into (and blame the healer when they die in fire).
Use the right spell at the right time. HEAL is now your default healing skill and should be used as often as possible. Unless there is something extraordinary (for example, a DPS gets hit by fire and is taking heavy damage), you should always be using heal on your party. The most mana-effecient way of healing the tank is: Chakra - Renew - Heal - Holy Word: Serenity - Heal. Flash heal should only be used in emergency situations or when triggered by Surge of Light. Greater heal is effective when you expect the tank to take heavy damange but still have some health remaining. A "Flash heal - Greater heal" combo will in most cases save a tank from dying. PoM is best used at every CD. Don't spam renew unless there is a DoT that your PoM and CoH together are not enough.
Read your meters. Especially when you are still trying to adapt to the new Cata style of healing, try check your overhealing after every battle. It's optimal to keep your overhealing rate below 5%. If yours is higher, take a look at your heal breakdown and see if you are using too many expensive spells on members that probably don't need them. Also, it is OK to not be casting the whole time in a fight. More activity doesn't mean better healing. When the damage is light, save your spells and mana for later. Another good way to use your meter is to look at what damage each member has received during the fight. This is especially valuable after a wipe, for you will be able to tell if someone has taken a lot of avoidable damage and remind that person to be careful, or if your party is using the right strategy in that fight.
Find good party members. I wholeheartedly agree that holy priests at this moment are very vulnerable to mistakes (of simply incapabilities) of other party members. A good Shaman of Paladin healer can probably save a dps whole stands in fire, but a holy priests generally can't, at least not without significant costs (large waste of mana or unecessary use of spell CD). To make your dungeon experience more enjoyable (or tolerable), you need a tank that is sufficiently geared for the instance and damage-dealers that can pull average amount of dps. This is why it is always a good idea to run through instances with people from your guild first, because these are people you know and (hopefully) are able to trust. LFD tool sometimes put you in really great teams, but in many cases you'll be stuck with at least one person that is either under-geared or has a very slow learning process.
I hope this thread has not become incredibly long and boring to read through. Again, I myself am also tring to adapt to the new Cata way of healing, so there could be many thing I forgot to mention or are completely wrong about. Please feel free to let me know and I will be happy to discuss with all of you.
Thanks.
EVIT