Let Them Come to You:
If you rush out into combat you'll be torn to shreds by both your enemies and your friends. Take on your opponents one at a time if possible.
Born to Lead:
Using the Q key to activate command mode is vital. When the firefight starts, use it to direct your allies' fire against especially tough opponents to take them out.
take any weapon and make it as your first weapon i like the minigun then take a good secondary weapon and equip it get in to battle hit 2 then quickly hit r then 1 you gan combine the weapons.