IMO
A good healer doesnt spam heal himself while soul stoned, watching the tank die. I use agunitframes, and nothing i hate more then watching my health bar slowly drain, seeing no faded bar indicating a heal is coming my way, tank and heals are top priority, if healer is soulstoned, tank is top priority, cant tell you how many times ive solo killed raid/heroic bosses from 50% on with just me and a healer because dps doesnt do what i explain.
I've even solo'd a handfull of raid bosses by myself with no heals from 40%-50% health on my own, which makes me want to punch people in the face when they whipe a boss fight because no dps is left or no heals when boss is semi close to dead so tank gives up (dps turning around and running because they "predict" that we might whipe is another button pusher to **** me off but were not talking about dps XD).
Also, healing talents are there for a reason, take advantage of any talent that will be beneficial. Some priests/pally's will argue that divine spirit/beacon of light arent worth putting points in, and it makes me laugh inside that they call themselves healers. those are the healers that in a tight spot, have no utility spells to keep the fight going and whipe on what could have easily not been
Dont over estimate your healing capabilities or get over confident about your healing, was in halls of lightning last night with a 75 priest that was actually getting rude with me when i stopped dps'ing (was ret at the moment and top dps) the pull before the 3rd boss and started off healing. this was approximately 5 whipes into the dungeon but it was a group of friends so no big deal till the healer got a little upset and said why doesnt she just leave and let me heal, because 3 dps makes it take longer, to which i replied "so does whipeing" (hadnt done it yet so didnt realize it was an 80 dungeon and probly wouldnt have gone with a 75 healer if i had known)
Not directing this at you, but dont blame bad healing on a lag spike/big hit/other person/etc, people arent stupid, as a tank im watching my health bar for incomimg heals, watching party health, and keeping an eye on the healer, and when i go down, i know exactly why i went down, wether it was bad healing, my fault, or a big hit, and in the rare occassion that i dont know what happened, i look at the combat log. Makeing excuses for why you couldnt heal in time, or someone got in your way, or a big hit that never happened, good tanks know whats going on around them, makeing an excuse that is an obvious lie to anyone paying attention only makes you look bad, and when im eating 8+ gold repair bills ill call you on it