I spec my 3 mages full arcane. I wanted to try out all the instant cast stuff and so far its pretty good.

My current cast sequence order is arcane barrage, ice lance, ice lance, fire blast. After this your arcane barrage should be back up to repeat the process. Everthing is instant cast so you can run around spamming it. There is a talent that increases the speed of your arcane missles. Its pretty cool and you can put out some major dps with the missles. Just be sure to hit follow again cause it stops you from following. With full arcane you will have POM so you can do a POM fireball then start spamming your instant cast attacks. So far I really love the ability to constanly run around and spam damage. Casting as a mage always seemed to get me killed boxing.

I changed the macro some.

/run SetCVar("Sound_EnableSFX","0")
/use 13
/use 14
/run SetCVar("Sound_EnableSFX","1")
/castsequence [target=focustarget] reset=8 Arcane Barrage, Ice Lance, Arcane Barrage, Fire Blast