Scout the field. When I get on a field before a game, that few minutes before the game starts, I get to high ground(if its available) and scout the field. Its easy to look at a field and get a pretty good idea how the other team will attack.
Also, know your marker. If you know your target isnt quit close enough, wait for them toget closer. I have seen numerous "snipers" blow thier cover, thinking I was close enough to shoot, and catch a bouncing pb.
I have an apex tip for a little added range, and it helps in those situations...you are out of thier range, but they are in yours.
And as mentioned before...pratice and patients.