Check my warlock for a good gear setup. He's in my My Twinks tab, Connecthedot.
You could choose Necromancer Leggings over the Shadoweave pants. (Post 3.1 as the PTR stands Blighted Leggings will be your top spellpower and Necromancer Leggings would be my suggestion due to needing to recover from stamina loss)
You could choose a BoA Shoulder over the green shadow wrath (top shadow power) ones.
You could choose WSG Cloak instead of the green shadow wrath one. (Post 3.1 I'd definately take WSG Cloak to recover from stam loss, green wrath is top shadow power tho)
You could choose Robes of the Magi or a green shadow wrath (top shadow power) chest instead of Robes of the Lich but lets face it Robes of the Lich looks the best.
You could choose SoJ instead of Kris+Umbral combo (+11 is best kris), I have SoJ and a +11 Kris (2 of them actually lol) I'm just too lazy to reenchant soulfrost.
Definately Revelosh's Gloves of Healing instead of Black Mageweave (I'm working on that)
You could choose Deathmage's Sash instead of AB Belt (top shadow power).
You could choose green shadow wrath (top shadow power) boots instead of AB Boots tho post 3.1 I'd definately go AB boots to recover stamina loss.
If you're lucky enough to have Lady Falther'ess' finger use that wand as its top shadow power.
Personally for trinkets I like to keep Rune of Perfection equipped for the Spell Penetration and use the other slot to swap between insignia, tidal charm, and engineering stuff/jewelcrafting stuff whatever.
Hope that helps.