This past week I got into some sort of alt raid. As I haven't been raiding they asked me to come. It went really well technically by bosses down. But by enviroment of vent it was pretty bad. Having main raiders paired up with alts and realtively new players was interesting. Healing at least was good.
I was healing with two other healers as usual. Although one was the alt of that guy who was basically leading the raid. I was rather low on the healing meter coming in third place and apparently he was a bit riled by that. (and the constant messed up kick didn't help) I had my excuse of having other things on my mind that night, but really why was I so low?
Our healing situation was him a pally, a shaman, and me the druid. He was good with his pally, I think he's leveled 8 or something. The shaman is normally the healer in my run, and she's pretty good except for her lack of gear due to luck. So of course going back to the meter I was low, I had high overheal a prime example of a bad healer.
With Druids we are all about HOTs, not as much as we used to be, but they are still our core mechanic. Hots of course have that nasty little over time part. I love the over time part, and if someone is not going to take more damage while the hot is sitting there there shouldn't be a reason to cast another spell until it is needed. In a perfect world HOTs would heal people the exact amount they needed before the next burst of damage came in.
However, in a world with a great pally and shaman healer I doubt those HOts are going to do much of anything. I have two options then: continue and appear to be horrible, or start trying to do direct heals. Switching to direct heals is just a horrible idea. You'd have to compete with two good healers who have better and faster direct heals. You would also be giving up your mastery in order to beat them to the heal.
Even if your hots were all going to overheal just having them up alows your speedy Nourish, mastery benifit, swiftmend, etc. This allows you to jump in when the other healers can't keep up and they need you. You should also have your innervate available for them. You will also continue using direct heals when they are needed, and keeping up one tank easily will benifit everyone.
This case was not as extreeme as I make it sound. It just brought up the thoughts. All healers should understand that there are more than one of you. Casting a spell that won't heal someone to full, but will combine with the 1-2 other healers to heal them to full will save everyone mana. The smaller the heal the more mana you save (except Regrowth!).
When healing with others you should try and understand how they are going to heal. They also need to understand how you are going to heal. We are all very different healers, but we come together to keep the raid alive. Add your mana to the other healers, use it as one unit to keep people up so they can kill the boss.