Remember not to spam Medica 2. If you need more AOE healing, you can medica or cure 3 on a target. I like divine seal+swiftcast+cure 3 on the titan breaks.

In 4 mans, it's more important to manage your aggro while keeping the tank alive. Dead WHM = dead party. I tend not to use regen or medica 2 outside of boss fights in DF since it's mostly speed runs anyway and those regen ticks can draw nasty aggro on those big pulls.