I run 4 ele/1 resto and use a combination of click healing + macros.

Essentially, click healing is for when there's focused burst that my resto can't keep up with... resto will change focus to that target along with using NS+GHW (NS if available) and the ele's will Healing Surge.

Normal rotation: For any DPS spell from the eles (LB, CL, LVB, etc) the resto has a click macro in that spot.

/click BTButton54
/click BTButton55

BTButton54:

/castsequence reset=6 [target=targettarget, exists, noharm] Riptide, Unleash Elements, Greater Healing Wave, Healing Surge, Chain Heal, Riptide, Water Shield, Greater Healing Wave, Healing Wave, Chain Heal

BTButton55:

/castsequence reset-6 [target=focus, exists, nodead] Riptide, Unleash Elements, Greater Healing Wave, Healing Surge, Chain Heal, Riptide, Water Shield, Greater Healing Wave, Healing Wave, Chain Heal

Basically, the macro runs the first button and if the target of your target is friendly (the no harm) it will cast heals on that target. So, target a dps, and you will heal the target they are trying to kill. If you target someone who has an enemy targeted (a healer) the first macro will fail because the target is non-friendly and proceed to run the 2nd macro, healing your resto's focus target.

Works, really well and effectively.