Specialty Specific Strategy
Ok, now we get to my take on more specific strategy for different people. You know you jobs better than I do, most likely, but here's my thoughts on strategy for assault, recon, sniping, and demolitions specialists.
I can't say much for assault. Mainly, always be alert and ready. And don't forget the main point of assault specialists - to assault! Let the snipers sit back and pick off stragglers, assault people should be on the offensive, and should be the main force. Don't get in to big a hurry, people always think of the game as fast paced, like you have to be moving quickly. That's not true. The enemy isn't going to get any smarter while they're waiting for you. The most effective way of assaulting is to move as a group, and try to take out enemies efficiently, covering each other and stopping periodically behind cover. Don't rely too heavily on the heartbeat sensor, it's a pain when you're shot holding it, and be ready to switch over to a pistol if you run out of ammo in a firefight. Remember also that if you're close to someone, sensor or not, they'll show up on your map.
Recon is tricky, and not many good recon people can be found. However, against an enemy team that's acting halfway like a team, recon can be a great asset. This hinges on communication, however. The main group can send out a recon man while defending their position. On his bound keys, the recon person can have messages such as "The enemy's to your left," or "the enemy's below you." Then when they make contact with the enemy, their first priority can be to give that message. Of course, that's not always useful, so recon specialists need a good background in assault. Thus, they should try and use silenced weapons when possible as well.
There are alot of snipers out there, but none I've ever met are flawless. They don't think logically at times, including myself. However, I think the goal of a sniper should be either to cover their allies, or to aim at a place where enemies are suspected to be, and wait for them to show themselves. They'll do it eventually.
Most snipers forget as well that they have time to aim. If they're in a good spot, they won't automatically be noticed. They probably have a few seconds to aim at the target and make the first shot count. If they're spotted by more enemies, or they fail to kill the target, they should move on to another spot. A sniper can't be seen, because the sniper is immobile while sniping, whereas the target can move around, firing automatic fire at the sniper. So the sniper has to kill the target before they can do anything about him/her.
Demolitionists most likely will need to serve more on the assault side of things in normal fights. However, a good demolitionist can be an extreme help in defending or assaulting an enemy who's stationary, like staying around one building, or hiding in a hallway. A demolitionist can have the place fragged before the enemy can run away.
Basic Movement/Commands - Level Specific Tactics