Gear from random drops is generally considered tougher to obtain than those from quests, rep or crafting. Unless you are uncannily lucky, or enjoy repeatedly running any particular instance, even a "good" drop rate of 12% can be a stumbling block to getting the piece of gear that you desire.
Furthermore, it is tough nowadays to find people who would want to run the non-heroic versions of 5-man instances - good luck finding people, or even guildies, to run more unpopular ones like the Auchindoun dungeons. With that in mind, I'll generally rate instance drops lower than gear from other sources, so that we can get your Warlock up to speed before WotLK is released.
Fortunately (or unfortunately), it's relatively easy these days to epic out your character before stepping into any raid content. The gear list below will prepare your toon - numbers-wise - for raiding, but experience, situational awareness and a correct attitude will still be critical to raid success.
As you venture into Karazhan, many of the gear drops will be equal or even inferior to what you already have. That shouldn't matter to you, since you're raiding for the fun and experience - not just loot - right?
Let's start from the top, literally:
Head: Spellstrike Hood
The Spellstrike Hood, part of a two-piece set with the pants, is well worth the investment of materials. The set will see you through the entirety of Karazhan, and even a good part of tier 5 content.
Before your guild can hit Void Reaver consistently for Cowl of the Grand Engineer or Hex Lord Malacrass for Hood of Hexing, no other piece of headgear, crafted or otherwise, comes close to the sheer PvE performance of Spellstrike Infusion. It is, however, a little thin on basic stats like Stamina - somewhat limiting its utility in serious PvP and later raids.
The more PvP-oriented Battlecast Hood can give you a good headstart in PvP, but considering the materials required, I'd say that the Dreadweave Hood is an easier and better option that packs Resilience on top of a solid +49 Stamina. All you need for the latter is a Honored reputation with the Cenarion Circle and 13g.
If you're not a tailor and you're running dungeons frequently, take note of the very nice Oblivion Hood (part of our "dungeon 3" set), that drops from the final boss of Arcatraz. The best head item from quest rewards at this level is the Evoker's Helmet of Second Sight.
Neck: Vindicator's Pendant of Dominance
This, again, is a great investment for a pre-Karazhan Warlock. For 15,300 honor points and 10 Eye of the Storm marks, you get this outstanding necklace that will last you well past Karazhan.
Alternatively, you can work your way up to Exalted reputation with the Shattered Sun Offensive for access to the Shattered Sun Pendant of Acumen and a whole host of other goodies. If you're diligent and complete all the faction's dailies every day, it will take just under two weeks to hit Exalted status. If you're exalted with the Aldor, the pendant will have a much more useful proc (+120 spell damage for 10 seconds) than the Scryer version (a random arcane bolt proc for about 350 damage). As a fresh 70, you'll probably be exalted with the Shattered Sun Offensive much quicker than either Aldor or Scryer. The stats on the pendant, however, are still respectable without the proc effect.
A great placeholder for this slot, while you work your honor or rep, is Natasha's Arcane Filament, a quest reward. Other notable neck pieces from dungeon drops include the Brooch of Heightened Potential from Shadow Labyrinth and the Warp Engineer's Prismatic Chain, out of Mechanar.
Shoulder: Frozen Shadoweave Shoulders
Along with the Spellstrike set, the Frozen Shadoweave (or FSW) set from tailoring is almost a must-have for most pre-Karazhan warlocks. While this set is only relevant to our shadow school of magic, the raw shadow power of these pieces is hard to pass up. The FSW Shoulders are easiest to make, in terms of material requirements. Note that these are BoP crafted items, and you need to stay as a shadoweave tailor to benefit from the FSW set.
Alternatively, if you have oodles of gold and you're on a server actively pursuing tier 6 content (Mount Hyjal and Black Temple), you may consider buying the BoE pattern for Mantle of Nimble Thought and crafting that instead. Note that the shoulders are BoP and require Hearts of Darkness, so this route is essentially a much larger gold sink than the FSW route.
As you gather the materials or gold to craft either shoulders, Spaulders of the Torn Heart are good placeholders for the shoulder slot. They are rewards from the pretty involved Cipher of Damnation chain of quests. An easier option is the Dreadweave Mantle, a respectable stopgap item with two gem slots.
If you want to try your hand with Lady Luck, both Spaulders of Oblivion, out of Shadow Labyrinth, and the Mantle of Three Terrors from Black Morass, are notable.
Chest: Frozen Shadoweave Robe
A raw 72-point bonus to shadow damage is a huge boost to any pre-raid Warlock's DPS. If you're a tailor, there is absolutely no reason to pass up this item, unless you find the material requirements onerous (some may argue that running instances multiple times for one elusive drop is more onerous). Like the Spellfire set, this robe will see you though a large portion of tier 4 content and heroics. You'll be hard-pressed to find good replacements for the FSW robe until you have 100 badges for the badge robes or when the tier 4 Voidheart Robe drops for you in Magtheridon's Lair.
If you are running Shadow Labyrinth or Mechanar frequently, watch out for Robe of Oblivion and Bloodfyre Robes of Annihilation. Robe of Oblivion deserves a special mention because of its three gem slots, and may serve you well enough to skip the FSW route altogether.
Unfortunately, quest rewards for the chest slot are probably meant as leveling aids. Shadowcast Tunic and Goldweave Tunic are both derived from Hellfire Peninsula quests, and you should probably have them already in the course of leveling.
The Dreadweave Robe, with 49 Stamina and three gem slots, should not be ignored as an easy interim measure. Its low spell damage bonus of 29, however, makes it less attractive compared to the PvE-oriented items above.
I'll wrap up this gearing guide in the next part of this article, but the gear choice for the feet and leg slots should be apparent from my recommendations above. Rounding off the FSW set will be the boots - which I'm still wearing as my guild works on Vashj. Spellstrike Pants will be the obvious candidate for the legs slot. In the meantime, young Warlock, start farming your primals!
V'Ming is dreaming of prancing up Mount Hyjal with his 24 friends.