Just be sure to order off the menu in any tea houses, I guess.

Also, I feel compelled to chime in on the subway topic. Basically, I only take it when I know it will save me time because taxis are still pretty cheap. What's more, any time a transfer is in the cards, I'd prefer to spend an extra few minutes in a taxi as an alternative. The People's Square transfer is a bit difficult to describe to those that haven't experienced it, but it's not cool at all.