Pull more trash That's pretty much it. We're fairly warrior-like in that the more damage we take, the more mana we have. If you're fighting three guys and barely taking damage, then you might want to grab the next batch of trash as well. This will allow abilities like Blessing of Sanctuary, Spiritual Attunement and Divine Plea to work their magic. There are some places this strategy doesn't quite work, which will make you have to change other things around in order to be effective.
No pants You could always just remove a piece of gear to lower your stats. This used to be a common solution to overgearing content, but with changes to things like Blessing of Sanctuary, certain glyphs and Divine Plea, this strategy isn't really needed as much. Rely on your skills and talents, not on your lack of pants.
Judgement of Wisdom One of the easiest ways of making sure you have more mana available is to judge wisdom instead of light. Yeah, no-brainer, but people often get into the habit of running around judging light, as it makes us more self-sufficient when questing.
Seal of Wisdom This really isn't a good idea. One of the issues when overgearing content is your lack of threat caused by no mana. Seal of Wisdom is a way to get mana back, but you're still sacrificing threat for it. So you've solved the problem, but kept the major symptom.
Seal of Command It's an ability, but it's a talent. I decided to put it here. This is actually a nice way to get free AoE threat if you're talented into it. The current Seal of Command essentially cleaves (yeah, I know it technically chains, but bear with me), which means each time you swing your weapon, you hit two other targets for some holy damage threat. There's also a glyph for the ability that helps out, but we'll talk about it later.
Blessing of Wisdom If you're too low-level to have Blessing of Sanctuary, this is an option for you. The one advantage that this has over sanctuary is that it is always going and not just when things are trying to hit you. However, if you can continuously pull with Blessing of Sanctuary, you should be fine.
Blessing of Sanctuary If you're above level 30, you should be using this as your go-to blessing. It boosts both your stamina and strength by 10% now, so there is little reason to choose Blessing of Kings over Sanctuary. You get mana from the dodges, blocks and parries you make and if you're overgeared, there should be plenty of them. The only problem is if you're killing things fast enough, they don't really have an opportunity to hit you. When in doubt, pull more trash.
Divine Plea Once you get this at level 71 and the prot talent Guarded by the Light (which you should already have, but more on that below), you should attempt to keep it up at all times. The problem is that some instances (*cough* Violet Hold *cough*) force trash to spawn so slowly that Divine Plea will fall off before the next batch of trash appears. However, keeping this active also falls into our "pull more trash" strategy.
Divine Sacrifice Yet another talented ability. While you could use this technique with Hand of Sacrifice, it's much more helpful this way. If you're in a fight where people are taking a decent amount (but not huge amount) of AoE damage, just pop on Divine Sacrifice and redirect it your way so that you take enough damage that Spiritual Attunement can make use of the heals. It's not an every-pull solution, but if you're in need of mana and people are taking damage, then go for it.
Retribution Aura If you're barely taking damage anyway, then might as well swap out of Devotion Aura and get a little more threat against things hitting you.
Spiritual Attunement Avoid two points; just put one point into it and move on. Being overgeared means you're not taking enough damage for it to matter, anyway. You usually want to leave a point in it for those fights where you are taking good damage. Plus, you can put that extra point you saved into Seal of Command over in the ret tree.
Guarded by the Light This is a wonderful ability when combined with Divine Plea. As long as you hit something with your weapon every 15 seconds, you'll keep Divine Plea up and running.
Divine Intellect This would help Divine Plea to give you more mana, but it's far enough into the holy tree that it isn't really worth it. You'll get more threat from putting points into the retribution tree than digging further into holy. Benediction I actually did a spreadsheet on this once. There are savings to be had, but through 18 seconds of your rotation, you'd be saving enough to cast one Holy Shield with a bit of change left, and that's with a full five talent points in it. Return for investment isn't that great for protection. I say avoid it.
Glyph of Seal of Command Probably your best bet for mana conservation. Judging costs 5% of your base mana. This glyph returns 8% base mana. That means every time you judge, you gain 3% of your base mana. That's around 100ish mana gain as well as your judgement ending up being free. Plus, you'll be doing more AoE threat with Seal of Command than with Seal of Vengeance/Corruption, when dealing with larger groups that die quickly. If you need the expertise from your Glyph of Seal of Vengeance for bosses, you could keep both or just carry a stack of both glyphs to swap out as you need them.
Glyph of Spiritual Attunement This is additive, so your Spiritual Attunement ends up being 12% max instead of 10% max. However, you're already not taking much damage if you're overgearing things, so that's an extra 2% of healing you're not using. Not a good glyph choice. Glyph of Consecration This messes with your normal protection rotation and should usually be avoided. Yeah, that's an extra two seconds of uptime, but the trash probably died about five seconds into the Consecrate anyway, so you'd be wasting the rest and have it on a longer cooldown. Lose/lose here. Glyph of Divinity Combined with the minor glyph for Lay on Hands, it allows you to pseudo-Innervate yourself. However, that's a major and a minor glyph slot to pull off that trick. You're better off with something else. Glyph of Shield of Righteousness This is one of our cheapest abilities already, so reducing it by 80% isn't that great. I agree with others that this might have been more useful as a minor glyph instead of a major. This was also a glyph before Guarded by the Light refreshed Divine Plea, and as such, it lost any appeal it might have had. As it is, definitely not worth its mana savings.
Minor Glyph of Blessing of Kings This is only really helpful at the beginning of an instance where you're buffing everyone. However, it does save a decent amount of mana in that situation, especially with the size of our mana pool.
Minor Glyph of Lay on Hands This is an old ret trick, to use Lay on Hands as a way to get a little boost of mana. Also, it gives you more access to the ability in case someone accidentally pulls aggro and you can save the healer or yourself.
Minor Glyph of the Wise It costs 50% less to use a seal you probably aren't using anyways. Uhm, no thanks.
The Light and How to Swing It tries to help paladins cope with the dark times coming in Cataclysm. See the upcoming paladin changes the expansion will bring.
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