How do i improve at modern warfare 2 in multiplayer?

use custom class if you have the option, its a must. i would suggest sticking to an assault rifle. the m4a1 carbine is a good place to start. i would suggest you use sleight of hand for the first perk, stopping power or hard line for the second perk and steady aim for the third perk. keep your kill streak rewards as the lower ones. for example uav, care package and predator missile or sentry gun.

you'll need to practice a lot. don't just rush into places. go in slowly, look at every turn and corner. i would suggest you play defensively, stay behind a few team mates never venture out alone. but please don't camp. task based games will really help you improve your game play.

practice it all doesnt come in one day