On sup'air it really depends on where you play.
There are general rules like, communication: Keep talking to your team and tell them what you see.
But front players have different things to do than a back player.
I play at the back so here is what I know.
As mentioned watch more across the field, right to left and vice versa. If both back players are doing this on one team then you see the entire play of the field and the people in front of you are already being covered. and cant get to you cause your back players are watching for you. (However that is not to say that you shouldnt look down the line as well)
As a back player you are not always looking for the elimination (however nice it may be) but are trying to keep the opposition in behind their bunker so that they dont eliminate your front players.
Some times you want to home in on one player for elimination but always when doing this keep looking around dont get tunnel vision or you will be mugged.
Again communication is the key to any game. At the back you have the best view of the field so let your front players know what is going on. they can't see much and need to know when they can move.
Practice is a good thing in paintball, and learn from your mistakes.
So now to go over to a mid and front player for advice.........