Build bridges. Forget Donald Trump’s bluster about a wall between the US and Mexico. Our jaunt from San Diego to Baja California shows how food bridges culture and communities – something that even he can’t muck up.

Bring back discreet dining. Informal restaurants (the kind where you share a table and maybe a plate) are ubiquitous but here’s to watering holes in which delicate matters can be settled over dinner and a drink.

Rely on regulars. One bad day can damage the balance sheet. More respect is owed to the restaurants that last and less to the flash-in-the-pan spots that close quietly just months after opening.

Don’t water it down. London’s River Café is remarkable. The self-taught chef’s passion survived the death of a founding partner to train a generation of chefs.

Treasure trade streets. Manhattan’s Bowery is a tale of New York’s gentrification in stove-top supplies – but these rootsy retailers may eventually be priced out.

Pack a punch. A trip to rural Kochi in Japan showed us that canny product packaging is a lifeline for rural companies being outpaced by inferior products with snazzier branding.

Perk up. There’s more to the black stuff than flat whites. We saw this while ambling down Tahmis Sokagi in Istanbul where crowds gathered to buy still-warm sachets of Kurukahveci Mehmet Efendi.

Market yourself. Food halls provide emerging businesses with a low-risk, high-footfall proving ground.

Take the initiative. Few people follow simple linear career paths and some of the producers we met just stumbled across their idea. That’s the case with Denmark’s only sea-buckthorn farmers.

Back to the land. Half the world’s population will live in cities and fewer young people are producing food. That said, the Tokyo grocer and Swiss farmers we met prove the case for bringing a city buzz to the countryside.