1) Get a bunch of friends/gamers to play together.
2) Get a nifty name, then use it's initals in front of your own. (Example: Crazy Nerf-Herders = CNF, so you would be CNF|Mad Cow, or -=CNF=-Mad Cow, or {CNF}Mad Cow, you get the idea. biggrin: )
3) As nStuff said, it helps to have your own server.
4) It also helps to have a webpage with some stuff (clanmate's info, members, tournaments, etc)