This is what I'm using on my (lvl 76) arcane mage:

/castsequence [nochanneling] reset=combat/target Arcane Barrage, Arcane Blast, Arcane Blast, Arcane Blast, Arcane Missiles

Reading the above posts, maybe I should dump the arcane barrage, but all my other characters start their dps rotations with instant casts too, meaning I can use it while they're still moving into position during trash etc.

I dont use click macro's at all, so if you're looking for something specific to that I cant help you I'm afraid.