Crosshair, FOV, and sensitivity are entirely personal preference. These things will not magically fix your aim. Try to quickly find something that you like and feel comfortable with, then get to work on your aim. The left/center/right handedness option does make a difference though, I already wrote about it once, so I'll just quote it in this thread.
I have made a little diagram to try to explain what the different hand positions do. The black X represents your crosshair, the circles represent the flight path of of the 'perfect' paintball leaving your marker(in other words an autococker with steel barrel). You'll notice that depending on the position of the gun in your hand, it starts from a left, centre, or right offset as it travels to the target. This provides a slight advantage in very minimal circumstances.
As much as people cry about it on the pubs, this entire game revolves around "spray", "lining", and prediction shots. Take a few maps and start looking at some of the angles on the choke points. Try to understand how your player's visibility comes into play from the perspective of your opponent. Always try to minimize your visibility, or identify key areas in a map where you'll be at the advantage in terms of seeing your opponents versus them seeing you. This isn't really specific to aim, but it's integral in you staying alive.
Depth perception and range is the main area where you'll probably spend most of your time starting off. There aren't many games like PB2 where these play such an important factor in every shot that you fire. Aiming with the correct depth perception and taking in account the range for the weapon/barrel is absolutely essential. You really need to put a lot of time in on carbines, automags and autocockers just to be able to compete in matches. Try to get a feeling of the firing rates of each gun, as well as it's shooting range and the impact that each barrel has on direction of the ball. A good practice is to start your own server up in the menu (with match-ish settings), load up a map, and type `debug1 1` in the console so that you can join whichever team and jump around without bots getting in the way. Start standing or running up to areas that you've already identified as being advantageous and getting a feel of where you need to aim to hit where your opponents are known to hang out. Your focus should be on getting the correct range to the same few openings or chokepoints from multiple locations in the map. If you're in a clan, you could practice with a teammate to spot where your shots are landing, or even have them stand/crouch at these certain areas just to get an actual idea of where to shoot. The teammate will also give you an idea of how visible your opponents will be, and will assist in understanding the depth perception of players, as opposed to fixed objects in a map.
At this point, you really need to start rushing into or through these positions and seeing how your shots land as you're in motion. Your movement has a slight influence on the speed of the paintball, so if you're moving very fast to your left, you can expect your ball to land to the left of where you were aiming, so you need to begin understanding how to properly counter-aim your shots so that they will hit what you're intending. The same thing applies if you're getting really high vertical speeds (up/down) like on a map like shazam33. You can't stand still in the open in this game, or you'll die. Running at someone straight on makes you an easy target as well, so you have to work a little left-right movement into your strafe jumps.
Once you've got the range of the guns down, you should already start seeing some improvements in your aim versus players who are moving. To hit moving players well, you really have to understand where they're going. It helps to be really comfortable in both range and depth perception, because you need to identify how far away the opponent is, and how far away they are going so that you can make a shot that will hit them as they pass or arrive to their destination. It's worth knowing that players who are taking huge jumps have very little control in their direction. Once someone has pushed off the ground, the arc of their jump will remain pretty consistent. If you're really good, you'll be able to shoot into people's jump paths, if they're jumping straight at you then it's even easier.
Try to see if anyone will send you some demos of them playing. Watch them and try to pick up a few things, whether it be: movement, aim, angles, game awareness, etc.; try to find at least one thing in that demo that they do better than you and improve on it. I've always felt this is the best way to learn anything.
-XB
While DT writes a thesis, I waste time writing stupidly-long DP posts to newbies who are probably too bothered to even read any of this. Hope someone finds some value in all of this...
