The one thing you must do in every city you visit

So much has been lost from the art of travel; so many surprises, enlightenments, awakenings. In every city, the streets are lined with Gucci, Loewe, Louis Vuitton, Gap and Zara, as if you have never left the airport's duty-free. But the local food market? That will be different.

I can't truly get the pulse of a city until I've been to the local market, dodged the flying cabbages, stepped in a puddle, been mildly insulted by a stall-holder, and bitten into something hot and cheesy or cold and juicy.

It's a short-cut to being a local instead of a tourist, just for an hour or two; to fantasise about what you would buy for dinner if you lived in that apartment up there, the one with the balcony.

If there's an art here – and we know there is an art to everything – it's to go early and go hungry. Nothing tastes quite as good as something handed to you in a brown paper bag before you are fully awake. You're eating tradition: flaky roti bread flipped and flopped before your eyes at Singapore's Tekka wet market; the sweetly warm, double-dipped tripe sandwich from Da Nerbone at Florence's mercato centrale; the meltingly cheesy crepes at Montreal's Jean-Talon market; the hard-to-beat bratwurst at Melbourne's Queen Victoria.

Allow yourself a period of meditative observation, where you lean silently against a column and just absorb what is happening, without taking a photo, without doing anything but breathing. Find something to focus on – the rhythm of the old fellow restacking the oranges for his son, or the matriarch in full make-up slapping squid against the side of the concrete tub, two cats at her feet. These are the moments that will stay with you; that stop the blur.

A good market will inform the rest of your holiday, with data to mine everywhere you look. You'll know what's in season, discover regional specialties – the pastiera cake of Naples, the snails of Turin, the salt cod of Barcelona, the dumplings of Chengdu – and meet the people who bring them to market.

Not just for photos, either. These people are trying to make a living, they're not here for your Instagram pleasure. You have to buy something: a baguette, a bag of cherries, some dried sausage, a wedge of cheese. It's a market, remember; a place of trade and commerce. You have to give as much as you get.