Equipment: What everyone should have

A force-fed hopper. These are relatively cheap, especially used. One that springs to mind is a viewloader evolution 2, (rated at 19 bps) which can be found for less than $30.

The ability to carry 500 paintballs. It doesn't matter how they are carried, just that they are. The easiest means is by carrying 2 pods with you onto the field, but vests work fine. Regardless of how much you "typically" shoot, you should still carry at least this much. As an example, look at Shamus in the first command post game. He recorded 7 or 8 kills, but ran out of paint when he had shots on 4 or 5 more.

Quality footwear. Basically, mid-cut or high-cut boots. We don't need ankle injuries.

There are probably more things to add to the list, I just don't know off-hand.