What class setup do you use when you knife? I have two knifing classes really, one with combat axes and one without.
If you use combat axes, it looks something like this:
Lightweight
Scavenger/Fast Hands
Extreme Conditioning/Tactical Mask
2x Combat Axe
If you don't use combat axes, it looks something like this:
Lightweight/Ghost
Cold Blooded/Scavenger
Extreme Conditioning/Tactical Mask
1x Concussion Grenade
I play very very aggressively. The great thing about Concussion Grenades is that while they're concussed, they can't turn as fast as you can run, even with stock. When you hit them with it, strafe around them to the side instead of running directly at them, and usually you'll be able to get to them faster than they can turn.
The scorestreaks I run when knifing are obviously UAV/Counter UAV/Orbital VSAT. Your only strength is knowing where your enemies are without them knowing where you are. Counter UAV is helpful even with ghost, for cases like if their team gets a VSAT or you're hiding around a corner waiting for them and aren't moving.
I think I have a youtube video of me doing it:
http://www.youtube.com/watch?v=eEvpJ9OuXlgPlay objective type game modes (not hardpoint/HQ, mostly dom) since you'll know exactly where they'll spawn and where they're going to be going.