I'll never forget the day that Feint first found its way to my hotbar. I was duo'ing Razorfen Kraul with another Rogue, trying to kill the pig boss (Agathelos the Raging) for his infamous Swinetusk Shank. After stealthing through most of the instance, we finally reached the boss. With creative use of Sap and Blind, we were able to conquer the guards outside his gate. That was the first time I actually used Sap!
After we engaged this gigantic boar, I picked up threat. I obviously used Evasion to reduce my incoming damage, but I had blown Vanish on the mobs outside and was unable to use it to wipe my threat once Evasion had ended. The boss was pounding me, I was sure to die in a few more hits. My friend began yelling furiously in party chat: "USE FEINT USE FEINT USE FEINT!!!!!"
I found it in my action bar just quick enough to press it before I died, and the boss turned to assault the other Rogue. I had exactly 1 HP left after the boar's rampage on me, and was lucky to have survived. So my partner used his Evasion, and the boss died. The Shank even dropped for me!
Feint has come a long way from its humble beginnings. Completely removed from every Rogue's hot bar in TBC, it's finally found its way back to our precious key bindings. By reducing all AoE damage by 50%, Feint is now both useful in PvP (think Bladestorm) and PvE. I've mentioned using it in a few of the specific encounters in Ulduar, but remember that taking less damage can be valuable on nearly any fight with AoE damage. This is especially true for hard modes, where you are often short on healing classes.
Feel free to think outside the box as well. There is so much raid / AoE damage in Ulduar that you can use Feint to some benefit on nearly every fight. Just make sure to remember that you must be in melee range of something in order to activate it, and that moving out of the AoE and taking no damage is often better than staying in and taking 50% damage. Don't use it as an excuse to play sloppy, but rather a buffer to ensure your mistakes don't kill you.
General Vezax, along with a few other mobs and bosses in WotLK raids, has some very important spells that he casts that must be interrupted. Most often this task will be assigned to a team of interrupters, with Rogues being the primary candidates. I would suggest using the mod Deadened to both highlight the spells you will need to interrupt, as well as reporting your interrupts to a particular channel. This will greatly reduce the amount of communication needed between you and the other interrupters in your rotation.
On fights where you will be doing a lot of interrupting, it may make sense for both your DPS and simple logistics for you to use a pair of the PvP gloves. These essentially yield 10 energy every time you have to Kick (and you HAVE to Kick) and so they can provide a ton of value in a long raid encounter. Don't forget that they also allow you to be more reactive with your Kicks, as you are now only waiting 1.5 seconds for the energy to kick (if empty) instead of 2.5 seconds. Just don't log out in them, or else face the wrath of Armory trolls everywhere!
I mentioned this in my key binding article, but I think it bears repeating. Tricks of the Trade is great for generating threat for the tanks, but if you're in a situation where the tank is safely ahead in threat, feel free to use TotT on your highest DPS class (that's not near stealing threat!). You can significantly improve your raid's DPS by assisting your fellow DPS classes in this way. Just be sure to ask for other Rogues to throw their Tricks back to you. It's not typically worth Glyphing for improved TotT, but even the normal version is a valuable additional to your arsenal.
The boss' back is huge:
I have seen quite a few melee classes die to silly things like a spot of fire on Razorscale or a gas cloud on Grobbulus. Their normal excuse is that they need to be behind the boss to maximize their damage. While this is true, remember that you can be ANYWHERE behind a boss, which leaves you with a fairly big arc to work with when attacking. Even though it looks like you're attacking the mob's hip, as long as you are in the 180° arc of his back, you will still benefit from the reduced dodge/block/parry chance of the boss from this position. This is especially important on fights like Mimiron, where knowing exactly where you can stand, in relation to the boss, is half of the fight.
The second half of positioning is to stay as far away from the boss at all times as possible. You want to ideally be just on the outside edge of where he's attackable from. This gives you an advantage in running away from AoE damage or effects, and also gives you a clearer image of the fight. If you are hugging the boss' ankles, you are obstructing your view and exposing yourself to unnecessary problems. This is especially important on Phase 2 and Phase 4 Mimiron, where if you are too close to the center of the boss, you can be instantly killed by his laser attack. For more info on positioning, I would recommend checking out TKoE's article on the topic (PvP focused).
Next week, you will be able to put all of these tips into action, as we talk about the final two bosses between you and the glory of conquering Ulduar! General Vezax and Yogg-Saron are basically Loatheb and C'Thun (with applicable twists), and I will go into the grainy details of how to defeat these two remnants from the days when the Old Gods walked Azeroth.