One tip I'd like to make to keep this going is the emphasis on patience.
Patience can be used in the right way and in the wrong way, as well.

The Right Way

When you have a sniper rifle and you're against another sniper and you're attempting to pick him. The spot you're peeking doesn't have the enemy visible, but you know he's there. The guy jumps out and tries to peek you, but misses the shot. Then for some odd reason, you miss your shot too. You don't peek out to try and pick the guy, you wait until the guy peeks again. Don't fall for the bait!!

The Wrong Way

If the round time is 2 minutes, don't camp spawn for 1 minute and 50 seconds. Don't pull a lin3ar or a Parik.