spacing and timing are big things as you get farther along. in lower level dungeons your 4 person team stays relatively close together. it's pretty rare that you have range issues or major AOE (area effect) damage from bosses to dodge. healing is more or less finding a nice place to stand and keeping people alive. pretty soon you will find yourself in situations where an 8 person team is running around like crazy dodging a never-ending cycle of stuff flying at them. if you can develop the ability to know where people are, keep yourself in range of them, and cast while moving from place to place, then you will have a lot fewer headaches later. i spent way too much time staring at the health bars in early levels, and it was a hard habit to break. try to get into the habit of planning your movement as you plan your spells. i think it will help a lot, if you aren't already doing it.