It's him... or you! Here are some basic tips on how to deal with your opponent in different situations in order to get that kill.
Before I start let me stress the importance of communication. Just the simple act of telling your teammates where someone is or when you are gonna move will help your team tremendously. If your team knows what's gonna happen and when then your buddies will be prepared and more confident when they play. Let's face it! Paintball is all about confidence. If you know something is gonna happen... Let your teammates know! Don't just think to yourself that someone is about to move. Say, "He's gonna move!" so your buddies will be ready to fire when he does.
Situation 1:
Let's say you are in a 1 on 1 situation and your opponent has good cover...

Now there are many ways to handle this situation but the best is to move, using cover, to eliminate his advantage of having good cover.
- Important note: When trying to circle, on the right in this example, try to shoot for the left side of your opponents bunker. This will make your opponent expect you from the left while you are moving right. ex.

While moving, Keep your head down and keep shooting! You might not get him yet but if you lay 20 balls on his bunker I'll bet he keeps his head down till you're ready. Circle until you have the best position and LAY HIM OUT!

Situation 2:
Lets now say that your team has 3 and your opponents have 2 well defended players left. Lets get them...
The best way to run a 3 man setup is one in the front, taking the heat...
With the others in the back for cover and to help the front man to move if the action gets too hot...

You should always focus on the opponent that has the best chance of eleminating a teammate or you but don't get tunnelvision. Far too often players will be so wrapped up in the guy they are shooting at they don't see other opponents moving and it costs them the game.
Situation 3:
You are in the worst position.
It's 3 on 1 and they are pelting you from every angle. WHAT DO YOU DO? Charge out of your cover to the middle of the field, guns blazing? Hide and scream, "Mommie" from behind your tiny piece of plywood?
Neither. Though you will probably be eliminated there is a chance you could survive. Always keep your head clear. Think about your situation and ACT!
Rush the man you have the best chance of eliminating and and move up fast!
With 2 on 1 it's usually better just to wait on the other team to move and get the first guy that pops up. Keep yourself hidden from the one while shooting at the other.
When he moves cap him and then just follow the rules for a 1 on 1 confrontation.
Remember, when you are alone ALWAYS be ready to move. NEVER stay put for too long or you will probably find yourself walking off the field with your gun held up over your head.
Easy as pie... right?
I hope this gives you guys some insight into team play and how to respond to some of the situations that can happen on the field.