My core rotation is simply: Blizzard III > Thunder 1 > Enochian > Fire III > RS > Fire IV x2 > Fire > Fire IV x2 > (Thundercloud/Firestarter Proc if any) > Blizzard III > Blizzard IV

Depending on movement I have to adjust my rotation. If it looks like I will not be able to get off a Fire IV for the second time, I use fire 1 earlier to keep Astral Fire III up.

I strongly feel that doing any casting before my core rotation is a waste of time that I could be using to cast Fire IVs. So basically, I go straight the point. I have not created a "Straight to the point" opener yet.