Well I got bored so I'm gonna post some tips you probably already know.
1. Don't shoot on sight. Most people are friendly unless they are shot at first. There is certain people who just kill on sight, but try not to make as much enemies so you don't have to worry about as much people killing you.

2. Claim Flags. I found this trick out the other day actually, if you see that an area is claimed you can pull out a claim flag of your own and check the area for where the area is claimed and pinpoint the flag location and take it out. Also if you're building, you can place them in trees.

3. Flank. Most enemies will keep watching the area that they last saw you in guns ready to shoot your face off. Tell your friend to distract while you flank him and sneak up behind to get the kill or Vica Versa. Try to stay behind cover and don't expose yourself while flanking.

4. Put a bipod on your machine gun. If you wanna keep a person pinned down or just keep spraying bullets down range the bipod is your best bet. It helps a lot with the recoil especially if you are in the crawling position.

5. Melee Weapons. If you wanna take a bed out quietly without the person hearing your gunshots, use a strong melee weapon to take it out. Don't use a chainsaw though. The sledgehammer is your best bud for this situation.

6. Night Vision. If the map nights aren't that dark don't use night vision goggles. The flash of night vision can easily give away your position especially if you're trying to sneak around in the dark. Same with the futuristic visor and all the future night vision stuff. Put on some Black Aviators or something, ID is 7700.

7. Don't trust everyone. Everyone may seem friendly, but they can easily teleport their friends who are ready to shoot and kill you.

8. Spawn Killers. I've had this problem too many times, and I'm pretty sure you all have had it too. Well it varies if you have a safe zone at spawn or if they are sniping from a distance. If you have a safe zone, do /maxskills (if it's allowed in there) and get the ♥♥♥♥ out of dodge. If they follow use the time to pull out a honey or a weapon ID you can type up fast. If they just snipe you as soon as you spawn there's nothing you can do about that other than just accept it.

9. Movement. Movement is key. Don't stay still exposed in the open for long unless you are teleporting someone real quick, because most of the time a sniper is scoped in ready to blow your brains out.

10. Use Third Person. Third person is the thing that can save your life if you're in a gunfight because you know exactly where your enemy is with that little vantage point you have over them.