Modern Warfare 2: How not to be seen?

Could someone actually show me how? Especially in Team Deathmatch when some spawny little sod catches me out of the corner of his screen and somehow gets the drop no matter that I've already opened the UMP up on him? The best that can actually be done is to have Cold Blooded Pro and Ninja Pro equipped along with silencers on both weapons, meaning that the only way someone can intentionally hit me is if I'm spotted in front of his face.

Which happens quite a lot.

Especially on maps like Wasteland where short-term camping gets you no kills, and Rust where any sort of camping gets Heather Mills' leg up your arse.

And even more so on TDM, when my 'team' largely does what it bloody well pleases and the other guys manage to work as a unit.

since some kind fellow posted a 'ghost' guide on CODNation , I've been sticking to the UMP as my main weapon, but wonder strongly whether I should switch back to an assault rifle. I quite fancy the SCAR for its snide power but the low magazine would necessiate a switch from Bling Pro to Scavenger Pro, meaning I'd have to choose between the tactical knife on my sidearm and the silencer. the M16 is also attractive but I'd have to avoid crowds for certain, so it's looking like either the M4 when I can have a little error-room, or I'd have to be bloody good with a SCAR/Tac-knife combo.

Either that or some hack-maestro can come up with a Predator camouflage on a killstreak. Just 10 seconds of near-full invisiblity would make the difference between -3 Kills/Deaths and +3 to me.