Shield Slam improves directly with shield block value, which not only adds to the amount of damage absorbed by your shield, but also to the damage your shield slams hit for. So more block value, more threat. This is not to be confused with shield rating, which only increases your chance to block an attack (and as such, is a pretty awful stat).
Revenge: Number two in your threat vanguard. Like a one-legged hooker, Revenge’s best asset is its cheapness. With talents, it can cost as little as 2 rage, and is your most efficient threat-per-rage ability.
Devastate: If Sunder Armor is still on your action bar, get rid of it. Devastate does everything sunder does, and more. It’ll apply a sunder debuff to the target, as well as additional threat and damage. Although it doesn't add as much threat after 5 sunders are applied, it still adds a decent amount, so don't stop using it (it will also refresh the 5 sunder debuffs for another 30 seconds). Use devastate if Shield Slam or Revenge aren't available.
Secondary threat moves
Whereas good knowledge and use of the above moves will get you through most instances as a much-loved and admired Champion of Threat, there’s plenty more you can do to go that extra step, and become a much-loved and admired Super Champion of Threat.
Heroic Strike: This could be thought of as the fourth primary threat move, if it wasn’t for the other three primary moves being so exclusive about their primary club. Heroic strike has some advantages and disadvantages. It causes some nice damage, and has a decent threat component. But it also takes 15 rage, and eats up your normal white damage swing (meaning you don't generate rage from that swing). Put simply, when you have limited rage, it is better spent on your primary threat moves.
The time to use heroic strike is when you have rage to spare. And here comes the advantage to this ability: it doesn’t rely on a global cooldown like the primary moves. This means you can spam it as often as you like during a fight and it won't delay your other threat abilities - the important part is recognising when you can use it without leaving you too rage-starved to use your higher threat abilities (eg. most boss fights allow for a liberal use of HS).
Thunder Clap: This ability’s main threat-use is in multiple mob tanking, which I’ll be discussing in another Essentials post. But it still adds threat to a single target, in addition to the debuff, so is sometimes worth squeezing into your rotation when against hard-hitting mobs (and essential on hard-hitting bosses).
Demoralizing Shout: The threat addition from this shout is very small, and is also divided between all the targets it hits. But a little is still more than none, so this can be a useful tool in attracting the initial attention of multiple mobs – especially as it’s not limited to 4 mobs like Thunder Clap is. The debuff itself is another essential mitigation tool against bosses wanting to eat you head.
Spell Reflect: This takes a hefty 25 rage, but used at the right time, can cause a very high amount of damage – and therefore threat. For example, in heroic Botanica, you can reflect the Greenkeeper’s “Greenkeeper’s Fury” spell for around 3k of damage. Mennu, the first boss in Slave Pens, can be reflected for about the same on heroic. This is not only a nice threat addition, but is also pretty useful in actually killing the mob - which, after all, is only behind “looking handsome and heroic” on the Hero’s Priority List.
Shield Bash: Although this ability does have a decent threat component, it's not worth using without the express aim of interrupting something - you simply have better threat options available. But when there’s a nasty fireball brewing in front of you, it’s another reason to make sure you bash some face.
Damage: Simply put, damage causes threat. This means the higher your white damage (the standard attack damage), or any extra damage you can push out from your abilities, the more threat you will generate. This is why strength, attack power and critical rating are not wasted on a tank (but note: expertise, hit rating, and block value are much better threat stats, for much the same reasons).
A Little Gnomish Knowhow: The ability of the Gnomeregan Auto-Blocker 600 is so darn good it deserves a mention here. The trinket is available for 41 badges, and has the passive stat of +59 block value - a very nice threat boost in itself. But the trinket's use boosts that value another 200 for 20 seconds - you'll be practically chopping heads off with your shield. That block value also translates into mitigation, as your shield will be absorbing a lot more damage. As such, make sure you make a space for this on your action bar, and use it as often as you can. A must-have for any threat set.
Emergency moves: Your momma's a...
Taunt: There’s good reason I’ve left Taunt to the end. It shouldn’t be a part of a tank’s regular threat-building considerations. Instead, learn to use it as a safety net, or an extra tool, rather than a necessity – and remember it can be resisted, and a lot of bosses will be immune.
Just to be clear on what Taunt actually does: when you taunt a mob, you will be given the threat value of the player at the top of the mob’s threat list (this is why taunt has no effect on your threat total when you already have aggro). Taunt also forces the mob to attack you for 3 seconds. This makes it only a temporary solution: if, after those 3 seconds, the player that you taunted the mob off has caused more threat than you (to be exact, 10% more for melee, 30% for ranged), the mob is going to remember he wanted to rip his head off. This means that during the 3 seconds you want to cause some decent threat to make sure the mob sticks with you. So follow up a taunt as soon as possible with any high threat move: Shield Slam, Revenge, Devastate, etc.
Although you shouldn't be relying on it for yor bread and butter tanking, there's no doubt you'll be needing a taunt sooner or later - there’s always going to be a time when your Shield Slam crashes into your own face rather than the enemy’s, while at that same moment the rogue next to you successfully hacks off 3 monster-limbs at once. The enemy will no doubt turn to the limb-remover at that point. So keep Taunt close, and in a convenient place.
Challenging Shout and Mocking Blow: Taunt isn’t your only emergency action. Challenging Shout does the same, if for multiple targets, but can also be used on a single target. It may have a 10 minute cooldown, but it also has a longer, 6 second period of forcing mobs onto you. Mocking Blow does the same for a single target, but will take a quick switch to battle stance. But importantly - neither of these abilities affects your threat total like Taunt does, so after those 6 seconds you'll still be below any over-aggroers if you haven't generated enough threat in the meantime.
Concussion Blow: Similar to the two above, the stun of Concussion Blow can give you time to get back on top of the threat list.
To sum up in some way...
Generating threat, like dps, has a lot to do with developing a rhythm. Practice with your timing, see what the most efficient use of your primary moves is on mobs and on bosses, then try throwing in some extras. If you haven't got Omen already, get it - it's a necessity for keeping an eye on your threat, as well as everyone else's.
Oh and pull faces and insult mothers. That always seems to piss people off, too.
