Taking you for a ride
Many scams involve gaining your trust, then getting you into a tuktuk to visit some temple/“elephant festival”/handicraft shop or other attraction. Having driven you around for a while, you will be dumped in some remote and seedy part of town at which point the tuktuk driver will demand a wildly inflated fare for the ride. Never get into a tuktuk without agreeing a fare beforehand.
You are offered free tea by someone claiming to own or work on a plantation, on condition you pay a “small sum” to cover the export duty or postage. Needless to say, the tea never arrives.
Fake charity collectors
Often elderly and respectable-looking gents with clipboards and official-looking letters; especially common around the lake in Kandy, but also in Colombo and on beaches everywhere. Real Sri Lankan charities do not collect on the streets.
Having a drink
You fall into conversation with a friendly local who asks if you would like to have a drink with him. Having taken you to some obscure drinking den, he claims to have forgotten his wallet, leaving you to pay the (usually vastly inflated) bill. Once you’ve gone, he will return to collect his share of your money from the bar staff.
The card trick
Someone asks you where you plan to stay. When you tell them, they produce a business card (purloined) from the relevant establishment and claim that they work there/are related to the owner. They then tell you that the said guesthouse or hotel is closed/full/undergoing renovations, then propose you come with them to their own guesthouse, or one where they earn commission.
A plausibly ragged-looking local engages you in conversation and tells you about the shocking poverty he lives in. He insists, however, that he doesn’t want any money for himself, but desperately needs a tin of milk powder so that he can at least feed his hungry baby. You are then led to a chemist, where a (surprisingly expensive) tin of milk powder is produced. Once you’ve left, he’ll be back to return the powder and split the proceeds.