Upvote:9
You're overthinking this. Do what's polite back home, and nobody will be offended, because people understand that you're a foreigner and not familiar with local customs.
"Asia" is also way too large a place to generalize about. If you're visiting a specific country, read up about its customs, and you'll learn about things you shouldn't do there (tramping all over tatami mats in your shoes in Japan etc).