First off, as every good healer knows, you have to have an addon to assist u in healing...something to help you monitor and control the way you can heal targets and control which spells are used and when.
I personally use quickheal, because it allows me to use macros I create and bind them to the healing spells as well. You can get that addon here:
Ok after you have got the addon, you might wanna create some basic macros to pop trinkets/2-3min cd abilities depending on what items/abilities you have. Now I'm gunna assume you know HOW to make a macro and so just a simple macro you would use with the quick heal addon would be:
#showtooltip Flash Heal (this line isn't necessary)
/use Trinket 1
/cast Arcane Torrent(Only for blood elfs)
/cast [target=unit] Flash Heal
Basically that simple macro should be binded to your left click in quick heal so that you spam this when needed and it'll automatically pop the trinket whenever available so that you get the most out of the trinket per boss fight. Arcane torrent is basically just like a small mana pot every 2 minutes, to keep adding to your mana pool as much as possible, you'll need it.
Some other useful macros for a holy priest would be:
/cast Inner Focus
/cast [target=unit] Prayer of Healing
Prayer of healing is one of the priests most useful abilities for raid healing, it's basically 5 flash heals at once. Since it's also quite mana costly, you'll wanna use inner focus to get the most out of it as possible.
Ok so those 2 macros are just some basic ones that I think every priest who raid heals should use, there are more macros that would help but it also depends on your play style.
Ok now that the macros are sorted, next is a breakdown of how to use the spells that you'll wanna focus on using and master using correctly. Some people may argue as to how I choose to use these spells but these are just my personal tips so please don't flame me if you don't agree.
Flash Heal
This should be binded to your left click inquick heal, set by the macro shown above. The reason is because it will be one of your most used spells and so it's easier to be able to just left click a target when they are low on hp. In a raid, you'll be wanting to try to heal those who are in need of the most healing (obviously) and so just pop ONE flash heal on them occassionally if you see that they have taken damage. The reason you want to only pop ONE flash heal is because there will be other healers in the raid ALSO trying to heal those injured people and so you'll want to work together with those healers and reduce overhealing as much as possible. The main purpose of using flash heals will be to improve Prayer of Healing through the talent 'Serendipity' which I will explain a little more later.
Circle of Healing
Regardless of the boss you are fighting, CoH is a very useful spell. The reason for this is due to it's instant cast nature, you can just pop it straight after a flash heal or a prayer of healing. (Just before the cast bar finishes, and it casts at the same time your flash/prayer of healing goes off). It's a great way to increase the chances of Surge of Light (talent) which means, instant CoH, instant and FREE Flash heal. Try to use CoH on the rest of the raid rather than using on the MT, because depending on raid composition and boss, sometimes the MT is seperated from the rest of the raid, even melee's who usually stand behind the boss and so there are less targets to heal with CoH. Use CoH on your raid, not MT.
Prayer of Mending
This is arguably the most mana efficient spell a priest has. Being able to bounce and heal targets whenever they take damage makes this a great raid healing spell. One of the disadvantages of this spell is that it jumps to the weakest and closest target in range, and sometimes that target is damaged just enough that the next hit kills them and so they aren't able to recieve any healing from this spell. The initial target of this spell that you should be using this on is the MT because he is always taking damage. However some boss fights, you can place this on a raid member who is a target of one of the bosses other attacks (e.g. Mimiron's Flame in phase 1) as an instant cast to help keep them alive longer incase a flash heal sometimes wouldn't be fast enough. Overall the main point is to try to keep a prayer of mending flying around the raid whenever the cooldown is up unless the fight is very low on raid healing requirement. In which case you should not use this spell to save mana.
Prayer of Healing
One of the best priest raid healing spells, being able to cast 5 flash heals at once, combined with the extra heal from a CoH and surge of light finish makes for one of the biggest healing combo in the game. Let me explain.
Prayer of Healing = 5 Flash Heals
Circle of healing = 5 Semi-Flash Heals (6 if you're glyphed)
Surge of Light = 1 free instant flash heal *non-critable*
Ok, so first thing, some people might argue that this spells' 3 second cast time is way too long and therefore unefficient at healing. However that's where the talent 'Serendipity' comes into play. Using flash heal 3 times to charge up serendipity 3 times reduces the cast time of this spell to the point that it basically takes as long as a normal flash heal. So lets look at some numbers:
Taking from my own priest who's geared with naxx25/uld10-25 level gear:
Flash Heal = 5k (7.5k crits)
Prayer of healing = 5 Flash heals = 5 x 5 (7.5) = 25k (42.5k)
+ Circle of Healing insta-finish = 5/6 x 3k = 15/18k
+ Flash Heal *Surge of Light* This is garanteed due to the 11 casts from prayer/coh, there will always be at least 1 crit. I garantee it.
Total: 25k/42.5k + 15/18k + 5k = 45k - 65.5k healing within 3 seconds.
Combine that with Inner Focus for the free prayer of healing with increased crit chance and you have the ultimate raid healing combo in the game.
Now you show me another class that has a 45k - 65.k healing within 3 seconds that doesn't have to rely on a cd ability beyond 30 seconds. This combo is repeatable everytime CoH is up and whenever you have 3 serendipity charges, although they aren't always necessary. Everytime you use this combo you already have 1 serendipity for the next one due to that final instant flash heal, so just another 2 flash heals (while CoH is cooldown) and ur ready to go again.
The main point of this whole guide is to try to help holy priests who I see healing with only CoH,Mending,Renew and Flash heal improve their healing because some of them will hesitate to use Prayer of Healing or not use it to it's full potential because they don't use flash heal as much, one of the healers in my guild who was also healing with me in the raid told me she only even used CoH and Prayer of Mending and I was shocked. So I hope this 'tip' helps those holy priest users out there and if anyone has any pointers about anything i've said here please feel free to contribute. Thanks.
