-Unless you are a sniper, always stay on the move.
-When playing as a sniper, finding a good hiding location is vital. Try remaining near an area with a lot of brush or shadows so you are not as visible. If you do not want a high powered rifle in an urban area, try the M21. Otherwise stay with the .300 Tactical or Barrett.
-Remain stealthy if your team is losing and you need a PSP. The enemy will likely be distracted by the rest of your team.