I think we need a little more info - are you level 70 doing heroics, or is this just instances while leveling or questing or what?

Basically I have a 5x LB macro that I use (the '2' key) - then, when I think my main (or the guy the mob is targetting) needs healing, I switch to my OTHER macro (shift+4) which has my first 3 shamans casting LB, and my last 2 casting lesser healing wave on the mob's target.

This works well in a lot of cases, as I can then switch back to regular LB spam when the guy is healed.

If that isn't what you're looking for, give more info and we'll see if we can help better.