I typically go invisible, run to some strategic spot that only a moron would use for more than 5 seconds, line up a shot, unload (grenade, 2 rockets, then IB round or 2), hit super, turn invisible again, and hightail it outta there. Typical example is the Factory on Spikis nightfall where you've got 2 Captains. I'll run to the platform near the door (where those dregs hang out) and hit them with everything I got. Then go invisible and get back to cover.