My rotation is as follows:
Blizz III > Swiftcast + Raging Strikes + Thunder 3 > Fire III > Fire I spam + Firestarter procs where applicable + Thundercloud procs where applicable > Blizz III when almost out of mana > Reapply Thunder 3 if needed using Swift cast again > If no need to reapply Thunder III, Fire III instead and rinse repeat from Fire I spam applying Raging Strikes always before the Fire I spam.
Apply your oGCD's for damage increase anywhere you wish or want to burst.