Since I started tailoring recently, I decided to grind for them, but it's actually harder once the mob is grey. If you can start the grind while it still gives you experience, such as at 59, you'll get a lot more bang for your buck.
Raids to Run
Ahn'Qiraj ~ 2000 rep per run
Things to Kill
Twilight Prophet - 60 Elite. Has 2 regular mobs as guards. Gives the most rep: 30 if grey. ALSO drops 7-10 Encrypted Text pages, which is how many you need for a 500 rep turn in, so never EVER pass one of these up.
Twilight Cultists - All the non-elites walking around the circled camps on the map. Gives 10 rep if grey.
Anything wandering around Silithus with a Twilight name.
Things to Gather
Encrypted Text - Drop off all mobs. Turn in 10 for 500 rep. Can buy off AH.
Twilight Cultist Gear
- Cowl, Mantle, Robe - Drop off all mobs. Can buy off AH. Used (and destroyed) at all Wind Stones, so you need multiple sets.
- Twilight Medallion of Station - Repeatable quest Dukes of the Council. Bring her 3 Abyssal Crests (see Lesser Wind Stone below) and 1 Large Brilliant Shard. Repeat for more medallions.
- Twilight Ring of Lordship - Rare spawn (non-elite) has high drop rate. Repeatable quest Lords of the Council. Bring her 3 Abyssal Signets (requires Medallion to summon boss to drop 1, see below for boss strat) and 5 Large Brilliant Shards.
Things to Summon
The bigger the Wind Stone, the more gear you need to summon its boss. Once you do, the gear you used is eaten up, it disappears from your inventory (if you have more than one set, the process will suck up a set from your bags, not the one you're wearing). You have a moment to change back into your regular gear (5-10 seconds) before the bad guy attacks.
Lesser Wind Stone
- Equip: Robe, Mantle, and Cowl (chest, shoulders, head).
- Summons level 60 non-elite elemental. Clear area around him first. Easily soloed.
- Receive 1 Abyssal Crest. Turn in 3 for 150 rep. Can sell on AH or give to a friend grinding rep.
- Equip: Robe, Mantle, Cowl, Medallion (neck).
- Summons 62 elite elemental Duke. Completable solo at 70 with potions, bandages, and serious buffing. Might want a healer to help. Soloable at 80.
- Receive 1 Abyssal Signet. Turn in 3 for 500 rep. Can sell on AH or give to a friend grinding rep.
- Equip: Robe, Mantle, Cowl, Medallion, Ring (finger).
- Summons raid boss. These have been nerfed but still require a group. Minimum of five competent, well-geared 60s or three 70s. Soloable in 80 raid gear.
- Receive 1 Abyssal Septer. Turn in 3 for 1000 rep. Can sell on AH or give to a friend grinding rep.
Almost all of the quests in Silithus give Cenarion Circle rep.
Head to the camp just west of Cenarion Circle town (see map up top). Grind mobs until you have a set of robe, shoulders, head. Summon an elemental boss at the Lesser Wind Stone. Get a feel for how that goes.
Start riding from camp to camp, looking for the rare named spawn (Twilight Lord Everun) AND the elite patrol that drops 7-10 rep pages (patrol spawns either in the north, walking from one western camp to the other, or in the south, heading up to the southern edge of the hive and back down to the camp).
After killing the patrol, stay and kill everything in the nearest camp for about twenty minutes, summoning and killing elementals at Lesser Wind Stones when you get the appropriate items to summon.
Then travel to the other camps to try and find respawns of rare guy and patrol. At least one should be back.
When your bags get full, go turn in your encrypted texts x10 and abyssal crests x3 (dropped from summoned elementals) for big chunks of rep.