You're playing 3 man so I'll drop some on field tips. The ones most new players don't quit know.
There are no front and back positions in 3 man. Your best option is for everyone to stay mobile. I've always preferred to stay off my belly in 3 man. Snake is cool and all but a lot of the time in 3 man the game is over before you can even crawl to the other side. Fast and silent like a bunny lol.
Try not to hit your bunker when you first get into it. Sure in some cases you may have to slide or dive in hard and hit the bunker but when making short quick moves you can go in quiet. If you get in quiet then you have the element of surprise and that's when you catch people, like eforce said above.
When you move bunker to bunker.....and you use suppresive fire stop shooting about half way to the new bunker. If you shoot all the way in, the guy you were shooting at will know you moved and where by the sound. If you stop half way he may not be able to pick out your new spot.........he may not even know you moved at all.
Gun fighting is silly. There are times when you need to do it.....but the best players use angles to eliminate players. In other words, you want to shoot side to side......not end to end. So dont focus on the guy in front of you, control him and plan on shooting his other guys from the side. Gun fights are 50/50 odds at BEST(if you both have equal skills). Catching a guy from the side where he can't cover himself is almost a guaranteed elimination with very few shots or risk to yourself. I see so many new players get pegged of gun fighting when they could have just ignored someone and taken out another target easy enough, or called for help from a team mate to resolve the situation. This is why crossing your guns is a great defensive posture. Less risk, more chance of reward.
Use your levels. Just because you're in a stand up bunker doesn't mean you shoot left or right. You have more options. High right, low right, high left, low left. If some dude is posting on you, mix it up! Fake left, snap right. Combos. Again, it improves your odds of winning. Jumping out in the same spots over and over, no matter how fast you are, gets you shot out. Be smart.
Communicate! Most guys go quiet when the game starts but you pretty much need to be talking most of the time. The only time you go quiet is when you make one of those unseen moves mentioned above. Then you shut up for a minute until you blind side someone. Then you start yacking when they see you. More information is always better and the game changes fast. The information needs to be constant......and repeated. When I play 3 man I never shut the hell up..ever! It's also intimidating to the other team. I've even won two 3 mans by talking to guys on my team who were already shot out. I knew they were gone but the other team didn't lol. I love mind games
When shooting, you don't shoot at players. Your paint is always one inch from the edge of the bunker he's in. If he's sticking out three feet.....you shoot the part of him that's an inch away from the edge of his bunker. Why you ask? Because in paintball you often miss! If you miss the part of him three feet out, he's going to get back in before you adjust your aim. If you shoot at the spot one inch out from his bunker.....even as he's coming back in your shoots have a chance to find their mark. It increases your odds of hitting him before HE adjusts. Basically it gives you more shots at him in the same amount of time. It's hundredths of a second but that's how the game is played.
Avoid playing the top of your bunker. While there are times that playing over the top helps...........for the most part it increases your odds of being shot. If you come out left.....only guys on the left of the field can shoot you. If you come out right, only guys on the right can shoot you. If you come up over top......usually anyone anywhere can shoot you(your odds drop). Now if you're way up on bodies the top gives you a great vantage point as well so you just have to learn the fine line. When I come up over top I keep myself very small and I move my head back and forth. That way if anyone is there to shoot me......a small moving target is way harder to hit than a large of stationary target. I've improved my odds.
Learn the blind shots. There are often spots where bunkers can block off certain parts of the field. Or spots where you can run and be totally shielded from certain players by these bunkers. Know them and use them. Why run through open ground when you can take a slight detour and come up on the guy totally safe? You can often make your own blind spot on any player just by moving in a way that puts a large bunker between you and him.
Blind shooting. Just because you can't see a bunker, doesn't mean you can't put paint into or in some cases behind it. I take out a lot of guys by arching shots into a bunker where I know there is a player hiding, but I can't actually see him or the bunker. For example.....if you're back right and he's back left but you can't see him.....you arch your shots over the very tips of the bunkers blocking your vision.....and they will drop down and onto him in the back left. You can even use your ears to help a lot. In this same case I won't shoot if he's looking tape.....but if I hear him shooting inside then I know my shots have a butter chance of taking him by surprise. There are tons of combos of blind shots, just walk the field and look for them. Blind shots are a fun thing to do when some dude is laying waste to the front of your bunker. No need to gun fight....send some volleys of blind shots out there until he gets bored and reloads lol.
When things go bad and you're alone........it's never fun BUT.....there are things you can do to improve your odds. Lay some paint on the closest guy and make a quick move.....then go quiet. If you can throw them off your trail for a second they may not know where you are. Then you can catch one off guard and even up the odds. If not.......try to get to a defensible bunker. You don't want to be in the snake or a small knuckle without a team lol. Stay in something big(more options). Try to position yourself where most of the enemy are in the same line of fire. This way you can maybe hold more than one down with little effort, giving you a chance to move out. If the flag is hanging still......make a break for it. Just do something other than giving up. If you fight it out you'll be amazed how often you can actually win. Guys get dumb at the end of the game when they think they'll win. Often they'll run straight at you without cover. Use levels and shoot them out. Just stay active.
That's all I have time for now lol