I've been running my level 70 Mage through some random (Utgarde Keep) Lich King dungeons, and finding that around 75% of the tanks I get are DK's. Which should make me feel good that DK's are up and coming, but many have no real idea what they are doing, or are very early in their learning stage. So here is the first of the HowTo guides to help people figure out how to tank as a Bloody Tank.
Pulling is where any fight starts, but some preparation work comes before that. In below end-game dungeons, or even end game dungeons when you overgear the instance, crowd control is no longer an issue. But if it is, CC should be the first thing you settle when you are facing a trash pack (or some bosses, like Hex Lord Malacrass in Zul'Aman). Mark them, or, if you have a good working group, the DPS will initiate their own CC. If you use CC, figure out where you are going to take the fight. Unless the CC is unbreakable (Banish, etc), you do not want to be too close to the CC'd mobs to accidentally break them. (Anecdotaly, I have put a DnD down on a Hexed mob, without it breaking throughout the full duration more than once. But this is not what you should aim for)
When that is done, make sure your buffs are up. Bone Shield should be up and whirling, unless it's on cooldown from the previous fight. Horn of Winter should also be up. Recast it right before your pull to give yourself a free 10 Runic Power. If you have a Warrior in your group (and no Priest), make sure they use Commanding Shout, and not Battle Shout so you can get both the Strength & Agility buff as well as the Stamina buff. Remind your group's Warrior every time he uses Battle Shout. Some need multiple reminders, or have Battle Shout macro'd into one of their moves. In return, make sure you maintain your Horn of Winter buff, as the Strength bonus makes them very happy.
The most important rule in pulling, and the one I see newer Bloody Tanks break the most in lower level dungeons, is DO NOT PULL WITH DEATH GRIP. Yes, Death Grip is cool, it's awesome and amazing, and leaves your party staring at you in awe as the mob just comes soaring towards you. However, if you end up Gripping one of the melee out of a group, and a ranged mob remains behind, you are left defenseless at his long-range attacks, and with a good chance at having your healer pull aggro from them if one of the DPS doesn't step up to CC it. Death Grip has a base cooldown of 35 seconds, which is roughly the duration of a single fight. Why would we waste one of our more useful tools at the start of the fight when we can utilize it better further on during the fight.
If you do not use CC, the best thing to do is just run into the pack, and drop Death and Decay down as soon as you get close enough for them to notice you. (Or maybe a little sooner, so that a HoT tick from a healer doesn't make them run for the healer before you get a chance to do anything). Once in their midst, hit a Blood Boil to get some quick aggro on all of them. Blood Boil does not have a limit on how many targets it can hit, nor what direction they are in (front/back), making it superior for getting threat on packs of more than 3 mobs. If there are only three, follow up with a Hearth Strike, if there are more, hit another Blood Boil. This should bring both your Blood Runes on cooldown and activate Blade Barrier.
If you do use Crowd Control, pick a spot not too far away from the mobs where you intend to tank. Target one of the non-CC'd mobs, and hit it with an Icy Touch to get it, and the rest of the pack, running towards you, and then drop a Death and Decay at your feet (or between you and the mob if you're still running towards your spot). When they get near, hit Blood Boil again. With it's unglyphed radius of 10 yards, it can provide some spot threat before they fully reach you. Again, make sure you use both Blood Runes in those first few seconds to activate Blade Barrier.
That is basically your initial pull. You now have some aggro on the mobs, Blade Barrier up, and are ready to position and tank the mobs so the DPS can take them down. There are some exceptions to these pulls, like boss fights, or some packs where a bit more effort is needed, or where we do actually need to use Death Grip during the pull. I will go into those in future posts.