General Tips and Tricks

The single most important thing you can do is to learn the maps well. Each map has areas in it that are bound to be heavily traveled through. Knowing where choke-points and likely objective markers are can make or break your game.

Know your abilities and class! Getting to know exactly what your abilities do and where and how to use them will help a ton.

Fill a role! This kind-of goes under the "Be a team player" category, but a team full of assault players isn't going to beat a team mixing Classes and Abilities properly! Perhaps your team needs more support players for revives. Perhaps no one is properly placing down spawn points! Be that guy (or gal) and help your team out!

Also, be adaptable! If the objective changes and one class (Support) may be better at defending than another class (Scout), do whatever is best for your team and objective!

Spawn Beacons! Their usefullness can not be over-stated! Make sure someone is doing this!

Try to check every avenue of entry when you are defending, although most maps have several. Still, you can increase your odds of surviving with turrets and other support abilities (or tactics, like the laser tripmine) blocking off one avenue of entry.

Use your Speed Dash ability for beacon missions!

Try all of the weapons until you find the one that fits you the best, then focus on upgrading it! Remember: abilities (attachments) are tied to guns, so factor that in!