Check your gem slots and enchants. Check your specs. You'll want to work on maximizing your character's production by getting gems and enchants that best help your role in the raid.

Every little bit helps. 

You don't want to walk into these high end raids with your clothes all wrinkled and stinking of gemlessness. Throw out a little bit of gold and get your least upgradable pieces hooked up by an enchanter.

If you need advice on specs or gems, ask google, or ask Mistake/Udazhi/Farwell/Redstate. He has researched specs for most every class and it's his thing.

Enchants and gem sockets are a big deal.