What is the point where you decide to start healing up your party members? That is, what's the HP threshold you'll wait for before you decide to pop your heals on the tank or other party members? Personally, if they dip below half health, I'll pop an Aldoquium then Lustrate or maybe a Physick or two if I'm synced below Lustrate level to get them back up to a decent HP count. If they survive to the end of the fight, auto-heal will handle the rest.

As a side note, I've heard tell of the idea that you're supposed to wait til there's one hit of damage left in their HP bar before you start healing them. I believe this is mainly the case for Savage content? I've never really seen it done myself and I don't consider myself a good enough judge of damage to do it myself.