South-East Asia: It's okay if you're trying to be friendly with a regular guy but if you're trying to get someone to work for you then you'd be better off not smiling and exchanging pleasantries or they'll rip you off.

"Hey, how are you? How much will you charge to take me 5 kms" would be the wrong approach to take with a taxi driver. Just try to look stoic (but not like an asshole) and you'd be better off.