This is how I heal heroics on my pally so far:
The baseline is beacon of light on tank, holy shock as often as possible (preferring non-tank targets), word of glory as soon as possible once I have 3 holy power (again preferring non-tank targets), and holy light on the tank as filler.
When more damage is coming in, divine light starts replacing HL. DL gets used more and more often as necessary.
When multiple targets are taking steady damage (aka HS and WoG aren't enough to keep the non-tank targets' HPs from decreasing over a period of time), light of dawn gets swapped in for WoG, assuming I can hit 2+ wounded targets with it.
Holy radiance is used here and there for AE damage, but tends to count as a "cooldown" in my usage.
When crap is hitting the fan, I use my cooldowns: avenging wrath, divine favor, guardian of ancient kings, lay hands, hand of sacrifice, hand of protection, aura mastery, etc. On fights where I expect/know that crap will hit the fan eventually, I'll use CDs early in the fight even when not really needed in order to help keep my mana higher for later in the fight.
I try to cleanse most/all damaging effects, but I tend to ignore most other debuffs because I don't exaclty have an abundance of spare GCDs or mana most of the time.
I never use flash of light, I still need work at handling LoD and HR. I'm only about 80% adapted to my new UI (all single-target heals except lay hands are on mouse clicks; I'm using grid and clique for the first time ever; my cooldowns and AE heals are on 1-5, q, e, z, x, c, etc., which used to be where I would bind heals; I rearranged stuff on my UI to try to have my eyes not need to move as far from grid to decursive to watching for fire, etc.).
In a good group (and by that I mean people know the fight mechanics, use that knowledge well most of the time, and the DPS are averaging maybe ~7k on any given boss fight), I basically never lose anyone, and I tend to finish fights without all my CDs on CD, and with more than 30% mana. With good CC I can be 3/4 afk and still heal trash; with a little CC I have to pay attention but it isn't hard. I tend to get comments like "nice healing" and "you must have great mana regen" and stuff.
In a bad group (meaning anything other than a good group), I oom a lot even on trash pulls, I complain about a lack of CC and an abundance of idiocy, and I sometimes get kicked for not "sucking it up and just healing."