Italy: let the man lead the way into a restaurant
In Italy, while it’s still generally considered polite to allow a woman to go through a door first, that rule goes away when it comes time to enter a restaurant. By heading in first, the man can be the one to talk to the host and get a table.
Italy: put down the Parmesan
In Australia, it’s customary for waiters to offer to sprinkle Parmesan cheese on your Italian dishes. In Italy, it’s not. In fact, it’s considered downright rude to ask for it, especially if you’re eating pizza. That’s because the cheese is seen as incompatible with pizza, much the way you might think ketchup shouldn’t go on salmon. That said, if a waiter does offer you extra cheese on a dish, it’s perfectly fine to accept it.
India: don’t eat with your left hand
When in India, avoid eating with your left hand because the left hand is seen as disgusting, as it’s normally used for wiping in the bathroom. The same is true for countries in the Middle East and parts of Africa.