If you really want the best choices in glyphs, you want to a) Look at the situations you will be tanking in and b) Make choices relevant to what you need. So to help you make this choice, we can take a look at each tanking glyph in turn.
This glyph works in all situations. It's a no-brainer to want extra melee damage mitigation and shield slam being a staple move in all warrior tanks rotations, this extra 10% will be up near 100% of the time.
Recommended For: Heroic Tanking, Raid Tanking.
If you're having trouble keeping AoE threat when you're farming your badges, this glyph is a good way to go - having that extra bit of damage on the target that your normal cleave just won't hit will reduce the chance of those pesky dpsers who attack the wrong target.
Recommended For: Heroic Tanking, if you're having problems with AoE threat.
While this is a popular choice, the extra sunders will not provide extra threat, it will account for some extra raid damage via the melee dps due to the armor reduction being up quicker. Technically you will have better starting threat as the sunders are up faster for you to do more damage but not really a good one to go for.
Recommended For: Very slight increase on starter threat, or if you want to marginally increase dps (by a small amount).
Not really a viable tanking choice as glyphs go. Heroic strike should be used sparingly during heroic 5 mans due to how much rage it eats up, using it on the odd occasion for that extra bit of threat. If you have heroic strike macro'd along side devastate, it's an efficient way to increase tps, only on a boss. And considering you're only on 3-5 bosses per heroic it's not worth it.
Recommended For: Nothing, don't use this one.
If you're considering this glyph, you will be wanting to think about glyph of shield wall too. The question here is, do you want the extra health every 2 minutes or a damage reduction every 3. It depends on the boss encounter, one that springs to mind (although not any more) would be Sartharion 25+ 3 drakes. This is evidently not a problem any more, however if you find yourself with an encounter like this one, you want a cooldown available regularly, in which case this would be a good way to go.
Recommended For: If you're having health/RNG problems on an encounter and need a cooldown regularly, otherwise it's a no-go.
When I was gearing my tank in heroics, I chain pulled very quickly and I found this glyph was good to speed up heroics for the impatient types in my group. It won't help in a great majority of situations but if you want to get through heroics quickly it can be handy.
Recommended For: Mid-range geared tanks who are farming emblems and want to get through a heroic quick. Not much point if you are poorly geared as it is likely you won't be pulling fast enough to need it.
As mentioned above, heroic strike will not be used much in heroics however if you are facing rage starvation problems on raid bosses, I'd recommend going with this. It helps a great deal having the extra rage if you have trouble gaining it. After using revenge use a macro combining heroic strike and devastate or heroic strike and shield slam if sword and board is up.
Recommended For: Tanks having rage problems on raid bosses.
To help out healers on fights, especially ones on-par or slightly above your gear level, this is a good glyph to use. The 2 minutes taken off this cooldown really help mitigate unwanted damage more often and you can use shield wall quite a bit more often.
Recommended For: Progression tanking, facing content aimed at your gear level.
Getting those stuns out on mobs 3 seconds faster can help out if you are running with a poor healer/your gear is bad or even if you just want some extra threat.
Recommended For: Slightly undergeared tanks or those wanting more AoE threat.
In my opinion it's a bad glyph, I can't see it being too useful in any situation outside levelling seeing as sunder does no threat.
Recommended For: Don't use it.
If you're losing threat often and in one of those rare situations where taunt doesn't work, this glyph plays a useful role. However I think the chance of taunt failing is a bit too low to consider this glyph viable so it's not worth using.
Recommended For: If you really don't want to use any of the above glyphs and want this one, but in a realistic world, it's not worth it.
This glyph can be fairly useful if you have threat problems, the 5% extra really is quite visible. Of course if your threat is fine then there is no need to worry.
Recommended For: Tanks who want to play it safe and get that bonus 5% threat from their nemesis on omen.
In summary:
Heroic Tanking (5 man) Glyph Choices: Rapid Charge, Cleaving, Shockwave/Blocking.
Raid Tanking Glyph Choices: Blocking, Shield Wall/Last Stand, Vigilance/Revenge.
I hope you enjoyed my first blog, feed back to me if you want me to write more, thanks!
-Io
