I have a big macro that pops as many CDs as possible, so i use Icy Veins, (arcane spec, with the leftover points in frost) arcane power, presence of mind, trinkets, etc. I also pop mirror image right at the start of the fight (for aggro help) and i use gems every cooldown. My mage is one of my worst geared toons, but does some of the highest dps.