The man drops his shoe brush in front of you. When you pick it for him, he offers to thank you by cleaning your shoes. At first it looks like a goodwill gesture of gratitude, but at the end you'll be required to pay for that.
An elderly woman offers a sprig of rosemary, a symbol of friendship. She grabs you by the hand and probably will tell you fortunes. After that she'll require money for the service. And if you won't pay, she'll begin to curse you and your family doing this very loudly and clearly.
When you're shooting, especially when you're doing portraits of each other, friendly looking local man offers to take a picture of you together. At best, he'll ask money for the help, at worst - he'll escape with your gadget.
The driver or rickshaw offers you any drug, if you are going to a party or an evening stroll. When you make a deal, there's a fake policeman grabs you and starts to extort a bribe for getting rid of the prison.