Are you going through your healing rotation properly?
No question has raised my wrath more than that. The idea of a healing rotation is my ultimate pet peeve. I once had a ret paladin ask me what my healing rotation was. Not even his bubble could protect him from my stony glare that penetrated his monitor.
Healing is all about a priority system. It's about who needs what healing spell when. So as you're progressing through all the normal and heroic modes that Dragon Soul has to offer, learn to cultivate smarter healing habits. Find out what you need to focus on. Figure out what crappy habits you need to break.
Coincidentally, Mike Gray wrote about the DPS side of spell priorities just the other day. He goes into great detail about the history of the DPS rotation and what developers were witnessing from the players. With healing, though, no real rotation exists. It's all about priorities. Two types of priorities exist: spell choices and healing targets. For players who are just getting started with healing, let me go into further detail about each type.