1. Calm down. I would wear my clothes and check myself on mirror, choose
shoe and wear socks. and blah blah blah just be normal~
2. handshake your opponent ; be cool and friendly with guy across you...
3. Use phychology only when you think you control the game
If you are losing don't hurry but think more carefully
4. After game, there might be recess. Wathc others play or grab a drink and talk with those guys.
Robin style : Everyone plays 1 or 2 times against everyone else. At the end,
the one with most wins gets the trophy.
That is all. Some complicated versions are out there though.
Win the tournament, you win prize or get a trophy.