First of all I would advise any Shaman worried about HPS to stop caring about it.
Your goal is simple: Keep your assigned targets alive!
There are two considerations you have to do before you even start healing, these are:
a) Is my gear up for the job, "is my character able to do the job?".
b) Is the job assigned overly punishing or too relaxing, "is the job able to be done by my character?".
Provided you're fairly confident they are, remember the focus is survival, not nice numbers. If I want I can pump out insane amounts of output by continuously CH-spamming the melee group at Lana'thel, but this may not be in the raid's best interest:
- One of the range-group healers is running with fire, happens to be a shaman (very little healing while moving), and I see targets in his group hit by shadowbolts => LHW to the rescue! The deal here is that I need to be fast about the heal (I got tanks to keep up usually), LHW has a high chance to crit so there's a fair chance it'll still heal my main target and I cannot guarantee the affected targets are in CH-range of each other anyways.
- Link goes up => RT one one of the link-targets => one more healspell on the main target => CH on that RTed linkmember. Hits while they're just close together in the center with maximum healpower.
- During Bloodbolt Whirl, I can ~depend on the Priests and Druids to blanket the raid like there's no tomorrow. Especially since Druids need the pre-spam to be able to Nourish. LHW is my superior option, mixed with RTs, since it is very fast, crits constantly, and the crits autotarget further low-HP members ~1,5s later, reacting to spikes faster than I can.
All three of these do not maximize my HPS. But all three of these are superior to just shooting for HPS, because they focus on survival.
-- (The Death of Rats, Terry Pratchett, Soul Music)