Stubbies said...
Keep an open mind...
Avoid 3rd world countries, (for some reason after I arrive there is always either a bombing, police action or coup d'etat and shots fired in my vicinity. I don't think I'm ugly enough to be shot at).
When booking a hotel always read the reviews, the good and the bad, (another blessing from the internet; pre-internet it was pot luck, and more often than not you had to be completely potted to get any sleep).
It's always wise to deny being American; learn the French, Spanish and Portuguese for "I'm Australian", and "which way to the toilet". You never know when either may come in handy.
Smile...
^^^ Agree
Always know the, yes, no, please, thankyou, hello, and goodbye in whatever country you are in.
And as Stubbies said, it's always wise to gently point out that your an Aussie, not a yank.
You'll find doors open much easier with those two tips alone
Smile with your eyes, not just your mouth
Don't be a dickhead, keep up Australia's good name (except maybe at Oktoberfest, but hey, it's a great challenge trying to keep up with ze Germans at drinkin )