I always open with Swifcast>Raging Strikes>Thunder III then hard cast Fire III>Fire>Fire etc.

I get myself down to around 700 MP, then Blizzard III>Thunder II or Blizz I depending on the situation if my DoT is still on or not. I'll swiftcast Thunder III if I have to dodge AoE's and Scathe to keep up the DPS along with any procs.

I can maintain around 200 DPS with i80 at the moment which I'm quite happy with.