I would recommend as an assassin to use the combination of stealth and mind maze in order to stun one non-droid enemy for one minute. In harder fights in PvE environment that may mean the difference between life and death. Learning to use that effectively will give you a chance to stun the strongest opponent and when he is stunned, to finish off weaker ones.
This is very good advice. (I just recently came back, Finnish, do the changes they made awhile back to CC not being broken by AoE also apply to that ability? I would assume so, which makes it rather awesome if this is the case.)
Another thing to bear in mind is smart timing. If you see you're about to be heading into a big group and your Deflection is down or you're not wanting to use it for some reason, re-pop your Dark Ward and wait a few seconds before charging in, so that if your charges get used up a few seconds in you won't have to wait on the cooldown to finish in the meantime-- it already will have by then, making it safely re-applicable.