As WhM I mouseover macro'd my ST heals and have never looked back. I'm normally dead against combat macros, but this just clicked for me and lets me react faster than without. I keep the boss targeted the entire fight, my mouse near the party list and if someone needs healing I can hover over their name, tap the heal key and continue dps'ing.

Worth noting it's not for everyone and macros can't queue, so it's a fraction worse than someone who can react fluidly without them.