My advice would be to go all out all the time and just keep pushing it and keep looking at the parses. You dont hit high numbers without taking chances, if you get aggro who cares, blame the tank
Ohh and on group mobs, make you are casting all your AOE's, including stuns, that power tap thing, and the mez, and the out of encounter (blue) mez.
Shit if I have a milisecond I even cast our fast single target mez to try and get a proc lol.
Examine highend illusionist also, i'm forever doing that, ask them about what items they have, personally i'm going crazy on crits and trying to get myself as much as possible at the moment.