Priest Tips
From Game Theory
Tips are arranged listing the more obvious first. For a good time, /join GTPriests.
Healy Tips and Tricks
Pre-cast
Start casting your GH's BEFORE the tanks takes damage, and cancel 2/3 of the way through if the tank ends up not needing the hp. Rinse and repeat. You will regen mana at a non-casting rate so long as the spell doesn't complete, and the tank will get their heals much sooner. Because a priest's main heals take 2.5 seconds, we have to cast proactively.
Smoothing spike damage
Shield + PoM are both great at preventing massive hits. Shield will prevent 1.3 - 2k damage and PoM will heal about 2k as soon as the target takes damage - taking 4k off large hits.
Inner Focus
Using this on Prayer of Healing will give you 5 chances to crit, making the most of your Inner Focus +crit.
Face a Wall
Healing has no facing issues. If for some reason you're having slow computer issues, face a wall and rely solely on your mods.
Use a good healy mod
Use a mod which places the whole raid's health bars in a small area of your screen, so you can see at a glance who's taking damage and you don't have to move your mouse far to select the next victim. Make sure your mod factors in range, and greys out etc. the hp bars of people who are too distant to heal.
Aggro enhancement
PoM is great for attributing aggro to someone else: such as when the dps is catching up to the tank, on the initial pull (it will make unlucky string of misses/blocks/etc irrelevant) or when the tank may lose aggro (cc, ..) and you need to avoid the mob hitting on you (seeing as the dps can't heal YOU through it). Each application is about 1K threat.
Keeping PoM moving
In most combats the healers are much less likely to take damage. If you have PoM on yourself and you want it to keep bouncing, SW:Death something.
Add debuffs to your healing mod
Add a few damage-heavy debuffs to your healing mod, so you can see when a player is afflicted with them and heal proactively. Whirlwind in Leo and conflag during Kael are great candidates.
Shadow Tips and Tricks
Do not cast holy spells
Cure/Abolish Disease will pop you from shadow form, costing you 800 mana should you want to return.
Inner Focus
You have 2 spells that can crit: Mind Blast and SW:Death. Using Inner Focus on MB will save you the most mana, has less chance of killing you and will do the most damage as MB > SW:Death. Using Inner Focus on Shadow Word: Pain is a very good habit for longer boss fights, as SW:P is your best damage/mana and damage/cast time.
Fade
Fade at the start of combat to prevent proximity aggro or pulling off the tank at the start of combat. Remember Fade is a temporary reduction, not an aggro dump - the threat will return in a few seconds.
Spell damage >>> everything else on your character sheet
...with the possible exception of Stamina, as "Dead Priests melt no faces." But since 2.4 both Spirit and Intellect contribute significantly to mana regeneration, and as long as you have mana, you can generate mana for your group. Of course for boss fights you have already capped your Spell Hit, right?
Spell Priority
Do not seek to memorize a spell rotation, as it will not help you in raids - instead know which ones are most desirable. Pre-1k + spell damage, avoid using mind blasts as it's too mana intensive and use mind flay instead. After 1k+ spell damage, use mind flay only when everything else is on cooldown. VT > SW:Pain > Mind Blast > SW:Death > Mind Flay
Abuse SW:Death
Unless it's going to kill you, use it. If you think it will stress out your healers, keep VE up so you can heal yourself through it. SW:Death is an important tool, don't gimp yourself by ignoring it.
Let your dots expire before replacing them
VT and SW:Pain tick at the end. If you replace them before they disappear, you're reducing your damage and wasting mana.
If you have a timer mod, recast VT when it says that it has less than 1.5 seconds left. (A bit less if you have significant amounts of Spell Haste.) Recast SW:P only after your timer mod says it has expired, no earlier unless you have a very good reason for doing so.
If your timer mod doesn't understand how to deal with the 2-piece T6 bonus, get one that does!
Mind Flay is 20 - 24 yards range
There are some combats where you can't use it. Most notably, Capernian during the Kael fight. *cry*
PVP Tips and Tricks
De-Sheep
SW:Death right before the sheep cast finishes, and the damage you take will unsheep you.
Sheep Protection
When the stealth cubes spawn, pick one up. The damage you take will be minimal, and it'll break sheep regularly.
Enemy Paladins
You may not be able to out-damage their heals, but you can Mass Dispel their infamous bubbles.
