One thing that I've had to keep in mind in 4e is trying to make sure I use my encounter powers, second wind, action points, etc. The "use it or lose it" resources, especially encounter powers, are important to make use of. It doesn't seem like your group is falling into being over conservative, so that is less of a problem. It will probably take a little while to get a good idea of when to use powers, but eventually the group will get a hand of it.
One thing that is good to get in the habit of doing though is testing the waters with some at-wills to start things of, figure out which creature is hard to hit, which are likely minions, etc. Eventually it can be possible to figure out based on what a creature is doing what defenses will be easiest to hit (which, depending on your class may or may not be helpful). Eventually it will help you to figure out whether to use an encounter power. Certain daily powers will depend on different things. A barbarians rage is bessed used early, since they get constant benefits, so it may be harder to determine when best to use it. However, with dailies that mostly do a lot of damage to a single target, and have few benefits afterwards, those are best kept for finishing off an enemy that proves to have a lot of staying power (figured out mostly be seeing how much damage it has taken already, and at what point it becomes bloodied, since that will give you a rough estimate of how much HP it has left) since finishing the threat off a turn or two earlier will likely save healing surges in the long run.