Hmm. I'll give my 2 cents. HM Titan down.

It's mostly about being smart with shroud, having party members that aren't shit and take unnecessary damage, knowing the strengths of healers and a little bit of team synergy.

Sub-shroud, you've got nothing really, so nothing to input here.

At 50, there are certain stages where you can fit a shroud before add spawns and have it off CD the next time it comes (Wall, Garuda etc)

Past that, it's having the tank pick up adds sometimes so that you don't waste a GCD on healing two targets (first boss AK, Garuda, although you'd be AoE healing Garuda anyway).

And also having DPS that aren't mentally challenged or lagging (getting out of weight, AK aoe zones etc).

Sometimes it's about knowing the fight inside out, such as possibly precasting med2 then med1 for titan jumps and stomps.

And finally it's about communication, if your bards have decent awareness, they'll ask for when you want song, and you'll tell them an ETA for OOM.