I know a lot of people who save Benediction for "oh shit" moments, for instance, but a lot of times it can be far more effective if you deliberately let the tank drop to about 30% and then slap Benediction on them. (Too much below 30% and you run the risk of them dying before you can get Benediction off, in my experience. Thank you, server ticks...) That leaves more options to heal throughout the fight, since you haven't blown through all your lilies and won't have Tetra on cooldown.
Similarly, I find it's often better to mitigate damage or rely on passive healing rather than healing actively when you can avoid it. When the tank settles in, I drop Asylum on them or pop Temperance (for the damage reduction). That means I have to do less healing in the first place, and I'm far less likely to run out of options if I
do need to heal the tank up.