How Do I Camp?
Camping it pretty much a no-brainer - all you have to do is stand and wait for your target to emerge from his base. When you see him, shoot him! Just one thing - Do not stay in the same spot for long; the enemy will eventually know where you are and launch grenades/rockets/bad-stuff at you.

But, just standing around on your battlements will be pretty tricky if there is a sniper on the other team's battlements. If that is the case, you'll need to move around and make yourself a harder target to hit. Move on to the next section to learn more about sniping in motion.