Today was my first legitimate tanking experience, doing two runs of Durnholde Keep. The first run was what you would call hesitant. My personal case of OCD means that by this point I've read every resource on DK tanking at least twice, and have read strategies for any instance I may tank in the near future.
There is a difference, though, between reading and doing. As I said, I took to the first run with great caution. The progression in Durn is actually really good for a new tank. It starts with a single pull, then a couple of double pulls, then some bigger group pulls in the prison camp. As the tank starts to become comfortable with these pulls, including marking and threat maintanance, he or she starts to move faster, make decisions with greater speed and ease, among other things.
I've found in fights against a single target, my rotation is precisely the same as my dps rotation. It goes as such:
IT > PS > BS > BS > Ob > FS > FS > repeat if mob is still alive.
Once you start to move into group situations, though, your rotation will change a tad. As a Frost tank, I have a few extra abilities for mitigation. Lichborne, Unbreakable Armor, and Icebound Fortitude are all great choices that can really alleviate the stress on your healer. These are abilities you may want to consider using whenever up in group pulls of 4 , especially if there is minimal CC in play.
In a group pull, my rotation becomes this:
D&D > IT > PS > Pest > FS on a secondary target > Deathchill > Howling Blast
For those not in the know, Deathchill is an instant ability with no cost and a 2 minute cooldown that makes the next Frost Strike, Howling Blast, Icy Touch or Obliterate an automatic crit.
What this means is that my Howling Blast at the tail end of my rotation will hit all of the mobs on me, doing extra damage because of Frost Fever, AND critting. This equates to about 2500 burst damage on EACH mob currently in my range. That pretty much cements my threat. After that, I move around each mob, refreshing diseases and doing some damage for extra threat cushion where needed.
Keep in mind, I'm still new to tanking. I probably have a couple of bad habits that I still need to weed out. However, the method I mentioned has worked for me so far.
Anyway, back to Durn. The marathon mob waves after the freeing of Thrall make this instance just that much better for tank training. You begin to understand the limits of your healer, and it is in situations like this that a Death Knight's mitigation abilities become useful. Keep this in mind: the less damage you take, the less your healer has to do, and the longer their mana pool will stretch. You want to be popping your mitigation abilities one at a time to make sure they last, each time they are off CD.
Anyway, on the off chance that anyone actually reads this, make sure to check back in. I'm sure that as I progress, my posts will become a bit more informative. For those levelling a DK as their first tank, I salute you. Keep going strong and eventually you'll stand tall and proud with the Warriors, Druids, and Paladins.
As an aside, for those interested, my stats in my tank gear/frost presence are 12.3k hp, 13k armor and 460 defense rating.