Trapping is not only for Canadian furhunters.. its one of the best paintball tactics too!
If you have another team member you can lay an effective trap for your enemy. It works against any number of enemies, but it is really important that one of you remains hidden. It obviously won't work if the enemy knows that both of you are there.
One of you hangs back and acts as a sniper. The other exploits the enemies excitement at seeing you.
You (the bait) head out away from the trap and fire some shots. Move around and make sure they know you are there, but don't be too obvious about it.
Slowly fall back (constantly moving of course) and lure the enemy into range of the sniper, who then opens fire. Now the enemy won't know what the heck is going on and you should be able to take out at least a few of them.
The key to this one is to a) keep the sniper hidden, and b) unload right when you have the enemy where you want them.
Have you had success trapping or using other similar paintball tactics? There are lots more here as well.