Being an oblivious pedestrian
If you're used to walking around one big city, you can probably navigate them all. But if you've never been to a place where walking is the main mode of transportation, here's a free piece of advice: stopping abruptly on a busy sidewalk is a great way to get body checked into a lamppost. Treat the sidewalk like the road, and the people like cars, and everyone'll be better off. Also, taking photos in the middle of the street's probably a bad idea just about everywhere.
Gianni Jaccoma is an editorial assistant for Thrillist Travel, and he's not usually this preachy, honest. Follow him, judgment-free, on Twitter @gjaccoma.