Once, when disembarking from a New York cab, I left the change from the fare as a tip. For me, it was a question of convenience; for the driver, a matter of extreme irritation. The US 75 cents left over from a US$12 cab fare were angrily flung at me at the cab sped away with a screech of its tyres, and the driver threw in a vulgar sign for good measure. (He had probably expected a tip of at least 10% to 15% of the cab fare.)

This is not to say that there are any hard and fast rules on topping. Practices and expectations vary from place to place, and you can toe the line or deviate from it if so inclined.

When and How Much to Tip

Both rule and practice vary from country to country. In Japan, for example, a tip is only accepted so as not to show discourtesy. In most European countries, though, a 10% tip in a restaurant is considered more or less mandatory. Across the world, the generally accepted amount for small gratuities given to, say, bellboys or room service waiters, is US$1 in developing countries, and US$2 in developed countries.

One rule is universal, however: never tip if you are dissatisfied with the service and there is no need to feel embarrassed about it either. Conversely, if the level of service has been outstanding, consider tipping even if the practice dictates otherwise.