I usually do as most other here, with the nova/shock/NS+CL

But If a fight is very chaotic, I have another emergency system that works fairly good if you get hit by several aoe'rs.

I first pop bloodlust, then I use a roundrobin chain heal (one shaman heals the next, then the next etc.

This will give you a really good aoe heal, and keep you alive while your totems do the job for you.

Note: this requires 5/5 talents in the interupt reduce for healing to work any good.