Do go to both East and West; stay in either the stylish Soho House (East) or the soothingly cool and reasonably priced Ellington (West). In many ways Berlin remains divided along the lines of the Wall. Mitte is the hip, post-communist centre, but its cutting edge has lately dulled. To the west, green Tiergarten and Charlottenburg are reclaiming their glamour. Or head south to Kreuzberg, neighbourhood of Turks, thinkers and drinkers.
Don't come in January and February unless you are a night owl. Weeks can pass without sight of the sun.
Do visit the Neues Museum. A bombed-out ruin for almost 60 years, it has been recreated by the British architect David Chipperfield and can now be read like a book, telling—through its original walls, surviving textural details, all-but-lost classical frescoes and soaring new spaces—the story of man's ability to create, destroy and preserve.
Do eavesdrop in second-hand record shops, especially the wonderful Long Player in the Graefekiez. CDs and MP3 are banned in this oasis of vinyl, with its special passion for hip-hop, soul, funk and the blues.
Don't eat currywurst, the ubiquitous grilled sausage served in lightly spiced tomato sauce. Save your euros for the daring, Michelin-starred Restaurant Tim Raue: DeSietra caviar on avocado ice cream, pink shrimps with Chinese rose wine and shiso and tissue-thin diamond label beef with Madagascar peppers. Goat's milk ice lollies, covered with white chocolate and fennel, clean the palate. Only the bill will be more breathtaking.
Don't repeat the fallacy that John F. Kennedy called himself a jam doughnut. In one of the most moving speeches of the 20th century, JFK said, "Ich bin ein Berliner". Nothing was wrong with his grammar, and no Berliner misunderstood him in 1963.
Do carry a beer bottle on the U-Bahn if you want to be taken for a local.
Do write a novel. In the cafés of Prenzlauer Berg, you can't swing a copy of "Alone in Berlin" without hitting half-a-dozen wordsmiths.
Don't go clubbing before 4am, especially if headed for Berghain, the world capital of Techno. In this converted power station, the bass beat grips the chest and pounds the body in waves so powerful that—in the second they stop—you feel like a dust mote floating up into the yawning cavern of the building. Ear plugs are essential, and not considered uncool.
Do brunch at the Café am Neuen See, a 1970s glass pavilion dropped into the Tiergarten park, surrounded by lush trees, flooded with light and fantastic nosh in the heart of the old West. Berliners have refined Sunday brunch into the planet's most relaxing meal with croissants and conversation, eggs, salmon and contentment washed down with litres of strong coffee.
Don't hold hands with your partner unless you are gay. Heterosexuals do not hold hands in Berlin.
Do indulge your sexual fantasies. The city abounds in (legal) sex clubs like the KitKat, "wellness" pay-as-you-go brothels such as Artemis and escort services for busy female execs. Tax receipts are available on request.
Don't ask a local guide, as one ill-informed tourist recently did, "Can you direct me to the Third Reich?" The guide replied, "Just walk down this street and turn right at 1933."