Play to your strengths, I do pretty well in the crucible. Warlocks and Hunters have range on their supers, so try to stay out of the open for too long. I'm not saying become a corner camper, but just play the corners. Also, rushing your opponent is sometimes effective, it's funny seeing their reaction when they see me barreling down on them. Also listen to audio cues, you can tell when a Hunter activates his super by the sound it makes. A Warlock with his super available is pretty obvious because he will try to get in close to use it, so if you see one being brave in cqc, stay away.