Effective use of Mind Freeze
One of the first steps to using Mind Freeze effectively is to set up a mouseover hotkey. One of the simplest mouseovers possible would look a bit like this:
/cast [@mouseover,harm] Mind Freeze; [harm] Mind Freeze
Essentially, this macro will cast Mind Freeze on your mouseover enemy target, or if no enemy is moused over, on your selected enemy target. This is especially useful if you're fighting one enemy but there's an add that can cast some spells that need interrupting. If you're a bit paranoid about where your mouse is targeted, you can use this macro:
/cast [@mouseover,mod:alt,harm]Mind Freeze;[harm]Mind Freeze
This one will only do the mouseover cast if you have the alt key pressed at the same time as you hit it. You may wish to consider setting up a macro similar to one of the above for Strangulate or Death Grip. That way, you have all of your interrupts available at a moment's notice.
Once you have a macro set up, the next thing you should do is look at your raid or group composition and find out who else can interrupt. With this in mind, you can help set up interrupt cycles and figure out which spells you can cover and others can cover. Just be courteous to others, don't shirk your duties, and remember that some people (such as the healer) may have better things to do than interrupt spells. Don't make other people interrupt spells just so you can churn out a little more DPS. This is your role. Live up to it. That goes for you too, tanks.
Finally, once you have all that set up, the next step is prioritizing which spells you interrupt. Sometimes, unless it's the only spell a mob casts, interrupting Shadow Bolts or Firebolts isn't worth it. Always try to save your Mind Freeze for the spells that need it most. These are generally going to be the spells that summon adds, the spells that heal, or high-damage AoE spells. Still, that's just a rule of thumb, and every encounter is going to have a slightly different set of rules for what needs to be interrupted or what can be interrupted. With that in mind, let's take a look at some of the heroic dungeons and search for the common spells that need to be interrupted. Note that this is by no means a comprehensive list but simply covers some of the most important places that you can put your skills in action.
A short guide to Mind Freezing in heroics
Shadowfang Keep Baron Ashbury's fight is very much interruption-based. If you don't interrupt well, you won't make it past this fight. Mend Rotten Flesh is going away in Patch 4.0.6, but there are still two spells to interrupt. Stay of Execution heals you, but it also heals the Baron. You shouldn't let it go for more than one tick if you want to have a chance at killing him. Pain and Suffering is the other spell. While this one can theoretically be dispelled or endured, your health will probably be low from Asphyxiate, so you'll want to interrupt it if you have someone else covering Stay of Execution.
In the rest of the dungeon, you can interrupt Lord Godfrey's Cursed Bullets, but with a 1-second cast time, it's going to be very hard to pull that off for many players. Luckily, this one can decursed on the other end. Finally, watch out for Drain Life from the Haunted Servitors. It can be out-DPSed, but it's probably better to just interrupt it. Of course, the other options is to simply steal it for yourself, which can be a great way to take some pressure off your healer.
The Deadmines There's not much interrupting you can do on the bosses here, but as far as trash goes, try to keep Defias Squallshapers interrupted. You can also interrupt the Holy Fire from Defias Envokers.
Blackrock Caverns There are quite a few caster mobs down here, so be ready with your interrupts. In particular, it's a great idea to interrupt Bore from the Twilight Obsidian Borers, especially if they have the tank targeted.
As far as bosses go, try to interrupt Corla's Dark Commands, because the last thing you want is for her to fear someone out of a beam, thereby saddling you with an evolved add.
Grim Batol You can interrupt Drahga Shadowburner's Burning Shadowbolts, but your big interrupts are going to be on the trash. There are a few caster mobs who can cast some pretty bad stuff, so be on the lookout.
Halls of Origination Temple Guardian Anhur's Reverberating Hymn needs to be interrupted ASAP. If you're the first one back on the platform, do it as soon as his shield goes down. Ammunae's Wither can be interrupted, although it can also be dispelled. Rajh will cast Summon Sun Orb, which should always be interrupted. The adds it spawns make the fight exponentially more difficult for most groups.
As far as trash goes, there's plenty of mobs to interrupt, but especially watch out for the Temple Shadowlancer's AoE.
Stonecore You can interrupt High Priestess Azil's Force Grip, but the most important interrupts will be on the trash. If you see a Stonecore Earthshaper casting Force of Earth, drop everything and interrupt it; if it finishes casting, you will almost definitely wipe. Learning how to interrupt or prevent the casting of Force of Earth is pretty much Cataclysm 101. If you take no other piece of advice away from this week's column, take this one.
You may also want to interrupt the Stonecore Rift Conjurer's Demon Portal. The adds it summons are manageable, but it's better to save yourself the trouble in the first place.
Again, the above is not a comprehensive list. There are other spells that can be interrupted almost everywhere, so don't be afraid to experiment, check stuff out, and prevent some damage and healing. You'll be upping your game to the next level, you'll be making your healer and tanks' jobs easier, and you'll be putting yourself one more step above the hoi polloi in the random dungeon finder.
Follow our road map to leveling your DK from 80 to 85, and then learn the ropes of endgame play with WoW Insider's DK 101 guide. Gear up with pre-heroic gear for DPS DKs and keep track of what's happening on your hotbars with our guide to DK spell alerts.