New York in three days

💡The tip isn't optional and the menu price isn't what you pay

In restaurants and bars you leave 18 to 20 per cent, and sales tax is added on top, since that isn't included either. Reckon on the final bill being about a third higher.

💡Pay for the subway with your bank card, and it runs around the clock

Tap your contactless card or phone at the turnstile, and from the twelfth ride of the week the rest are free. Check whether the train is local or express: the express skips twenty stops.

💡Several museums have a pay-what-you-wish evening, and you still have to book

MoMA on Friday afternoons, the Whitney on Fridays, the Guggenheim late on Saturdays. The free tickets are released online days ahead and go instantly: set a reminder.

💡Apply for the ESTA before you buy the flight, not after

It's the entry authorisation for Europeans, it costs little and is usually approved in minutes, but it can take up to seventy-two hours. Apply on the official government site: the others charge you extra.

💡Twenty blocks uptown is a kilometre and a half

Numbered streets run east to west and avenues north to south; with that you can't get lost. But a block crosstown is three times longer than one uptown: check the map before you say you'll walk.