EA guys weren't lazy enough to make Sniper Rifle bullets as straight vectors. They have decay and you must take it into account.
The head is very temptating to shoot at. Then shoot it!
It's very unadviseable to teabag your enemy if you are going to hold that position. It may have a Dead Man Trigger.
It's okay while you still hear the shots. But if you don't...watch your back.
Pistols aren't decorations. Don't rely blindly in your primary.
Switching to you secondary is always faster than reloading. Pulling out your knife is even faster.
Unfortunately you can't shoot through walls. If someone does that, it's the lag.
An always moving soldier is harder to hit. Then shake your skeleton!
A good sniper will always change his position after every kill...even if it's a step to the left.
Mounted rockets kill. Don't underestimate them.
If you have a fighter, don't go straight forward upon an engineer. You may take a RPG into your face.
Who said that tanks can't blow up jets?
If your helicopter took a tank shot, get the hell out of there.
A good weapon isn't actually the one that have more damage per shot, but is the one that hits every one.
Motion sensors don't explode so don't waste bullets on it.
Try throwing a mine at the side of a stopped tank. Fireworks!!