Some of this is already posted but:
-Watch your feet, even if you're at a standup bunker. You may occasionally have to step on your other foot to keep from getting shot out. Another trick is to keep a pod inbetween your knees. It prevents you from sticking your foot out when you have to lean out to shoot. Even Poorman from Avalanche has this problem. If it's a large laydown bunker, you may have to lean way out to shoot past the "bulge" and your feet or knees may be exposed long before you can shoot.
-watch your hopper. It's usually the first thing everyone sees...even if YOU think it's not visible. If the top of your bunker is sloped, you may have to lean your hopper over or shoot from an unconventional position.
-walk the field an learn the blind shots. It's possible to shoot at a position you can't see (usually by shooting over the top of another bunker), and actually hit someone. If you're shooting high in a standup bunker, and someone shoots at you, you may be able to tuck in, and look out from the bottom of the bunker to see where the stream of paint is coming from, if there's a smaller bunker inbetween you both, and then shoot back, from that lower position and either hit the shooter, or push him in so that you can stand up again and then keep him in. It can also work off the break when you're sweetspotting...just because you can't see the runner anymore doesn't mean you can't shoot him or at least get him to change his path.
-learn how to make love to your bunker. If it's low and round, and you're on your knees, push your hips into the bunker as if you're horney, you haven't had sex in a month, and you're looking for a hole. If it's tall and round, push your hips into the bunker as if you're horney, ...
-If you're a runner, the best path to your bunker may not be the shortest path. Sometimes running so that a bunker is between you and the shooters, and then cutting a 90 degree turn at the 50 can be the best path...unless your mirror on the 50 posts up on you and starts shooting even before he sees you.
-in practice, jump into any "snake" as often as you can and scoot for the far side as fast as you can. In games, only jump in if you know you have a good backman, or if the other team isn't watching the snake from the tape. Memorize what angles you have when you pop up in certain spots and don't pop up in the same spot twice, don't shoot more than two balls, and don't go head to head with someone who posts up on you. Tuck in, stay down, and trust your backman to keep anyone from bunkering you and either move to another spot, or wait for the posted up guy to forget about you and look for other targets. If he's good, he won't forget about you, and his field captain will yell at him for shooting at other targets. Most likely if you get popped it'll be on the hopper or the lens, if you're not bunkered. If you're waiting to get bunkered, get in really tight...push the bunker around you if you can, point your barrel up to the sky, and listen for either that short stutter step that happens when someone's bunkering you, or that vibration of your bunker when someone hits it, or alot of yelling and screaming followed by a shadow. Just start shooting before you see anything. If it was a ref, he should've announced that he was coming (I played Merry-go-round with a ref once...he ran to check me and I thought he was someone coming to bunker me in a skinny standup rocket so I chased him, he chased me, we did a full circle, my backman shot out the player screaming for the paintcheck on me, I pulled the flag on my second time around the bunker and we hung it) and if he doesn't...well there's a reason everyone hates reffing.
-If you're at a standup bunker and you're the last one left and there are 3 or more guys coming for you, figure out which one is closest and most likely to come bunker you, then either tuck in or shoot the opposite side so you can lure him into the open, then pop out and try to catch him in the run. If he's like most people, he'll come running for you with his gun down and you can pop him. I know someone who took out 5 guys doing this and snap shooting smartly. If someone's pounding your bunker, don't trade with him directly. You might squat down and shoot UNDER his paint, you might just tuck in for a little bit 'til he reloads and hope that he wasn't smart enough to move up on you, you can shoot the other side of your bunker, or even wrap around the front of your bunker (scary but sometimes needed) to shoot out the guy from an unexpected angle. If the bunker is partially deflated, don't just make love to your bunker...push into it so that it fluffs out around you and FORCE someone to come and dig you out. In the last Seattle Pan Am, it was 1-on-5 and the other team was shooting so much paint that they started deflating my bunker. I pushed in and shot out the guy who came for me. His immediate reaction was to start yelling at his teammates for letting him get shot out when there were 4 shooters on my...I got shot out immediately after I shot him (the other tape moved up) but needless to say, I was rather pleased with his reaction
-sometimes, if the field is really small, it's smarter to have only 1 or 2 runners, and the rest of you post up and lane until the other team has settled into their bunkers.
-If possible choose bunkers you can stand up in if you're a backman. If you're a mid or forward, try to choose bunkers you can at least be on your knees in...a standup bunker is ideal, but rare.
-Don't ever shoot over the top of your bunker unless it's a preplanned shot (you have a picture in your mind of what you're shooting at before you can see it) and don't shoot more than 2 shots when doing so...pop back down immediately, don't try to admire your handiwork. Ask your backman if you shot someone out if you're not sure.
-If there are only two of you left, and the other team has three or more, try to move to standup bunkers before they start zoning in on you, and then Cross Up. This means that you shoot twards your other tape, and your partner shoots tward your tape. This assumes you're both separated so there's not a blind lane in front of both of you. Your goal is to not let your partner get bunkered, so it's best if you both setup in bunkers with lots of clearspace in front of them. This is where you'd better hope you have plenty of paint left 'cause you'll be shooting alot of paint in order to prevent the other team from even getting a chance at snapshooting you out. If your partner gets bunkered, it's your fault. If you get bunkered it's his fault. The ONLY reason you look down your tapeside is if the bunkers are situated such that your partner can't prevent them from coming for you. They WILL get close, but that's why you ignore your tape and shoot lots of paint to keep each other alive. Some team captains even teach their Crossed Up players to not even spin if they're getting shot in the back. They just keep shooting and yell that the other guy was shot before he shot them...trusting that their teammate shot him out before he got to them. Why not spin? If there's anypaint on the other player, he can't claim that it came from you when you spun after you were shot by him. In order to continue shooting in this situation, it takes complete confidence in the fact that your other teammate really DID shoot out the runner. You can't even blink 'cause most likely someone ELSE is running to bunker your partner.
Whoops! I think I ran on too long...I haven't even covered wrapping around, moving without getting shot, shooting on the move (a gun with an eye helps when doing this), and making those trick shots
I hope this helps.
Ray