Currently at 23/36, should hopefully get Subtlety Rogue down before the end (had a 3% wipe earlier today after 4 attempts). That will leave me with Druid and the three classes I've yet to level for the next time it's available (DH, Monk and Priest). I would say I felt I needed Ravaged Seed Pod on Destro Warlock and Outlaw Rogue, both of them seem pretty annoying, especially Outlaw with the RNG Roll the Bones, if you don't get Grand Melee procs your only personal healing is Crimson Vial and the leech from Grand Melee is really big. On a few of my attempts RNG was that bad it never procced (
https://pbs.twimg.com/media/FIObysUX...jpg&name=small). Assassination also felt to me like it had survivability issues, but thinking about it now I could have use the oil that heals, however my DPS was low (my trinkets were not great, 2 x Insignia, didn't have anything else) and I just about killed that with CC after they had enraged (killed the Jarl, CC'd Queen and killed the Caster/repeatedly broke shields).
For my Shaman, I didn't use much in terms of crafted or special consumables. My Enhancement was just SL gear that I remember and Ele/Resto had a Garrosh Heirloom.
Most attempts so far were Prot Paladian (54), Blood DK (48), Holy Paladin (35), Restoration Shaman (25), Destruction Warlock (25). Everything else was less than 20. Easiest for me were Fire Mage (1 - Absolute joke), Fury Warrior (1 - I haven't played Fury much so basic), Arcane Mage (3) and Survival Hunter (3 - Accidentally hero'd on Xylem pull 2 and wiped at 10% CS, would have been a kill otherwise).
I think knowledge of the fights helps greatly, as well as watching videos and the WoWhead guides can be pretty useful, especially the comments. My Sub Rogue was able to get straight to CS on the first pull of Xylem due to my knowledge of the fight and watching videos.