It's said to be good manners to tip your waiter, taxi driver, hairdresser, doorman and so on.

据说，给服务员、出租车司机、理发师及门卫等支付小费是一种礼貌的行为。

youdao

Why am I supposed to tip a cab driver, but I'm not expected to tip the bus driver?

为什么我要给出租车司机小费，而不用付公交车司机小费呢？

youdao

Why am i supposed to tip a cab driver, but i'm not expected to tip the bus driver?

为什么我应该给出租车司机消费，而不必给巴士司机小费？

youdao

But Hearts came roaring back and Alan Combe did well to tip Andy Driver's looping volley over the bar before Elliot struck.

BBC: Hearts 3-1 Kilmarnock

If you take a taxi, tip the driver 15-20% of the bill, plus a few extra dollars for extra service such as helping you with a heavy bag.

FORBES: Plane Jane: Travel For Business Like A Pro

If you're taking a taxi in Chile or New Zealand, for example, the driver won't give you the evil eye if you don't tip -- it's not expected.

CNN: How to tip outside the States