From what I've seen, if you can get a group of guys together who work as a team, they basically steamroll over the opposition.
Tips I've learned so far:
1) ALWAYS aim for the head. The headbox so large that headshots account for 1/2 the kills in any given game.
2) The only time you should stop moving is when you shoot. You get much greater accuracy by stopping/crouching. Try it out sometime with long distance shots. Running = wide pattern Walking = smaller pattern Stopping/crouching = tight pattern
3) If you've never played before, ignore the trolls who keeping telling you "Hit F10 to get more money" or something like it. F10 simply exits you from the game.
4) If you can, follow somebody and stay in groups. You're MUCH more likely to live if you have buddies providing additional firepower.
5) If you're running/walking and somebody starts shooting you and you aren't near cover, alternate crouching with standing. It keeps your head bobbing up and down and makes it harder for them to get a headshot.
6) If you see a grenade being thrown (enemy or friend), look away for a second. It could be a flashbang grenade. Flashbang grenades are even worse than High Explosive in my mind. You're completely blinded for a good 5 seconds which is more than long enough for an enemy to come up and kill you (and three of your teammates)
7) Always keep your crosshair at head level and pointed at a possible enemy hiding point. You never know when someone may pop up in front of you.
8) If it's late in a game and there's only a few allies/enemies left, crouch down and slowly creep where you need to go. You can hear footsteps a lot better when there's only a few people left and it can give you advance warning that somebody is coming up on you. If there's no blue dot near you on the radar, it's an enemy.
9) Watch your radar. When a teammate spots an enemy, you will hear "Enemy spotted" and the person who spotted the enemy will flash orange for a few seconds. You'll know where at least one enemy is.
10) Fire in bursts. Simply holding the trigger down results in a wide pattern. Letting loose with 3-5 round bursts results in much better accuracy.
Anybody else have some tips/tricks?