1. DO NOT BE LOUD.
2. Mingle with locals
3. Don't shout USA/be patriotic
I suck at this.
I really might be soiling the good name of America. I use good lightly here because I know most people have a crap view of American(s). But most seemingly want to visit the good ol' USA. I myself am not a huge USA fanatic. But I mean people are people wherever you go and no one has the perfect Utopian country.