Okay, I finally get to do one. This attempt was primarily motivated by whiners on the WoW forums talking about how we lack even the most basic skill.

Shadowfang Keep - cleared fully - level 22 holy priest and 4 affliction locks.

General strategy - Succubus is good for this one. Keep them on passive and have lash of pain on auto-cast

Of note - It helps for the locks to have amplify curse, especially on the last boss (although this may be a problem since they all leveled inside the instance to 23 and I then specced it, but I think it can be obtained before). Use amplify curse with Curse of Agony so that the 4 locks end up doing something like 1200 damage just from that spell (on a single mob). The last boss had by far the most health (4500 or so) and you're going to need everything you can muster since he has very nasty abilities (control a group member via worgen transformation, ranged posion attacks that HURT, and a teleport where he just up and runs to the other end of the room).

Certain worgen in the instance, although I don't recall their label now, are immune to shadow spells, so take them on one at a time with immolate and let the succubi handle him.

The wailing guards cast a silence that lasts for a few seconds (but it seems like a lifetime). You're not going to fight them in anything but a group of two at minimum. The trick is to immolate, corrupt, and CoA to a single mob right off the bat and send the succubi after the second. When the silence wears off, have the locks dot up the other mob tanked by the succubi while the priest heals the locks / pets if needed. Sometimes they appear to come in groups of three, but that's just because one is patrolling. Wait until he's gone to ensure a good pull.

The worgen Moonstalkers (or some type of worgen with 'moon' in their name) will cast an anti-magic shield during combat so be sure to have cast anything you want to get through before this happens (usually, you just have time enough for no more than three dots per lock). It will wear off after a few seconds, but they are vulnerable to melee damage even while it is active. Usually, if things are planned and pulled well, you can alternate between two of these at a time since one likely has it's shield down (they appear to be based solely on time since when I am killing quickly, they don't cast at all, but that may be proven wrong with more observation).

Other than that, just be aware of the boss fights since Arugal will summon four voidwalkers after you kill the second-to-last boss. My priest actually died during that fight. Anyhow...

One thing I noticed, and this happened enough not to be my fault, was that the succubi would randomly attack the wrong mob all together, not at all the one that I had the locks targeting. This caused a wipe or two, but I was usually able to deal with it since I kept the priest at full mana.

Like I said, the final boss fight was a real stretch, but that was mostly due to my inattention paid to healing. Now that my healer has quite a few upgrades, I plan on going back a little better prepared to gear the locks.

I had a blast with this and encourage anyone with the means to attempt it to do so.