Try to move and control the exterior of the map, while looking in toward the middle and taking advantage of people fighting there. If you aren't great with a particular type of gun, say fusion rifles for example, spend 3-4 hours doing everything you can to only use that gun type. That will logically lead to you working to control secondary ammo spawns, and it will lead to the other team having less of those (shotguns) available. Little things like that will help both your game and your team's performance.