So far I've only been doing the primal trails, not in the mood to do dungeons yet as from what I remember the end game community can not be so great if you don't do what you should be. So far for the trails I've got Swiftcast > Thunder 3 > Fire 3 > Fire 1 (repeat till low MP) > Blizzard 3 > Thunder 3. Then using procs as you've said as and when they become available.