Some weapons (m4 med for instance, and a properly used ak74) lend themselves well to hipfiring if need be- though you never want to do this unless its either last resort, or you're using it with another trick when moving from place to place at short range which I'll leave to you to find.
Always, always, always, always iron sight, short of having absolutely no time to react; you'll nearly always win against people of equal or lower skills if you iron sight and they don't.
And my personal favorite- rush. Rush, Rush, Rush, if you aren't rushing you're doing it wrong. See that smoke nade that just got tossed by charlie? Rush the smoke; chances are you'll catch someone with their pants down as they either still have nades equipped or are trying to swap back to their main. See that nade in front of you? Rush past it- nades are used as an area deterrent or for indirect fire- either way, they won't expect you on their side of the nade until after it blows up. In summary, rush. It surprises most and solves nearly every problem.
