Totally agree with Charlie about China – Chengdu is OK, Guangzhou you’ll get f’d – with the addition that there are _lots_ of scammer hot spots around the world, if you’re for example, from Egypt, you wont get taken in China — because shit gets real in countries where you arrive at the airport and the scamming begins literally before you pass through customs (by people who don’t actually work in the airport).
Anything feeling a bit weird, just make sure you have a phone number of someone that you can call and verify whether it’s legit.