First off if you not using an exotic primary, you are most likely putting you self at a disadvantage. It really helps to compose a team of different strengths. My team usually consists of two snipers and a shotgun. This helps cover the different types of fights you will have. Stick together. You don't need to be right on top of each other but be close enough to either team shot or get revives. If you don't already snipe, I would strongly suggest becoming one. It lets you get kills at a far range so you don't get killed be shotguners. Also many people in trials snipe do you can combat those people. Don't play to the enemies strengths and don't do what they want you to do. Change things up a bit go different way to mess the enemies up. A few other tips are avoid choke points, don't be afraid to run, COMMUNICATE, and don't rush to much. I play on 360 if anyone would want to play My gamer tag is alexdog9999