CHRISTMAS is just a day in New York. However, the build-up, from the moment the Thanksgiving turkey has been picked clean to close of business on Christmas Eve, is something special. Winter will have cut summer's riot heat. The sky will have turned a deep arctic blue. And as the Christmas lights go on, menorahs - candelabras used to celebrate Chanukah, the Jewish festival of lights - will appear in many windows. Granted, there is a tacky side. One of the many temporary jobs I had when I lived in the city in the late 1970s was tossing tinsel on synthetic pines in department stores. I was the appointed elf of a painter friend, an enormously tall and witty man from Washington named Romero Trotsky Williams. These days he makes his living painting. Back then, he used to make a huge chunk of his yearly income decorating Christmas trees. It was not that it was particularly well paid. He was just fast. When it came to the trees, his motto was 'Make haste, not taste'. Other decorators, however, took it more seriously. 'Good thing they didn't hire us,' Romero remarked admiringly as, one dark December afternoon, we watched the skaters in Rockefeller Centre. The surrounding trees and shrubs were beautifully lit. Then, somewhat jealously for two such hit-and-run Christmas decorators, we concluded it was not so difficult to make New York look festive. It was a city of lights all year round, we told ourselves. Christmas lights simply made the dazzle somehow official. Even the huge red Calder mobile hanging in the Guggenheim Museum looks Christmassy. Office workers in red coats look like Santas with blow-dries. Fire trucks look festive. And throughout mid-town, shoppers carry the bright red bags, filled with stiff red boxes, which are the Christmas signature of Saks Fifth Avenue. But to judge by the label-dropping in Vanity Fair and among the guilty yuppies in Jay McInerney novels, Saks is out. Apparently the store of the moment is Barney's. Here, we are told, young men buy blazers that require a mortgage. Yet most New Yorkers are not the fickle, bored rich we read about and see in Woody Allen films, but simple city dwellers and fantastic grafters. The average annual holiday is two weeks. Hence, New Yorkers understand the task, reward, task, reward, mentality. A suitable reward for a day's work is a meal at the Grand Central Oyster Bar in the cavernous cellar of that famous train station at 42nd and Park. Last time I was there a woman, surrounded by her Christmas shopping, sat alone at a long counter facing an enormous tray of oysters on cracked ice. The Grand Central Oyster Bar has a long and wonderful list of California white wines. However, be wary of sampling too many of them if the shops are still open. I made this mistake once: next thing I knew, I was at the famous toy store FAO Schwarz, waiting for an assistant to box up a 1.5 metre-high, rather fetching stuffed gorilla. Next day, sober and remorseful, I posted it to the daughter of friends in Cupar, Fife. When the postman wheeled the huge box up their drive, they protested they had not ordered anything. Reading the customs declaration, he simply replied: 'It's a gorilla.' Which brings me to an important bit of advice: one of the many casualties of the Reagan era was the United States postal service. Not long ago the best in the world, it is now slow and infuriating. Buy only what you can carry, or send it home with Federal Express. Better yet, walk a gift to yourself to the airport: buy a good pair of cowboy boots. Do not attempt to break them in on New York pavement. Manhattan Island is pure rock. The secretaries you see loping off to work wearing running shoes with smart suits may look inelegant, but they are not stupid. The best way to see New York is from the water. Weather and season allowing, the best-ever tourist float is the Circle Line trip around Manhattan, boarded on the Hudson at the westerly end of 42nd Street. The tour guide's endless patter is delivered with such delirious enthusiasm that, on stepping off the boat, one could win a quiz. The Staten Island ferry runs in all weathers, without running commentary. A return trip costs next to nothing and affords wonderful views of South Street Seaport, Wall Street, Brooklyn Heights and the towers of downtown Brooklyn. Only real commuters get off at Staten Island. Having warned you off the post office, it may seem strange that I now recommend seeking out cards. New Yorkers are postcard-mad, and the museums have fantastically good gift shops in which to stock up on Holbeins and Karsh portraits. Good on ingeniously engineered pop-up cards is a shop in Greenwich Village at the corner of West 12th and Hudson. Even the New York Public Library at 42nd Street has a shop which, last time I looked, sold a wonderful selection of old baseball posters and cards. The queues forming around the church-run soup kitchens up and down Ninth Avenue may look like something from the '30s, but they are all too modern. When Ronald Reagan came to office in 1980, he said he was going to separate the needy from the 'truly needy'. He succeeded so vividly I somehow doubt the New York Times still has its quaint habit of printing a Christmas list of the city's 100 neediest. In my day, the Village Voice, a brass-necked investigative weekly, famously used to counter this with its own list of New York's 100 greediest. Shop till you drop SHOPPING in New York requires stamina, so start off with a high-cholesterol breakfast at Jackson Hole (Madison Avenue at East 91st). It's the ultimate New York diner, all red ketchup, green pickles and thick white cups. Either sit at the counter for pancakes, crispy bacon and maple syrup, or get there before 10.30 am, for a window seat on Madison. Then head for Bloomingdale's (third Avenue at East 59th Street). A New York institution, its flashy black-and-white marbled entrance halls exude perfumes and high-living. Good for gourmet foods, it has a whole shop devoted to caviar. Not quite as chic as it once was. Barney's New York (Seventh Avenue at West 17th Street, and Madison Avenue at East 60th Street) has superseded Bloomies as the department store. It boasts the best-dressed windows in the city and inside it's wall-to-wall Calvin Klein, Donna Karan and harried New Yorkers. Let your purchase be swaddled in gift wrapping bows. Macy's (West 34th Street and Broadway) is NYC's biggest department store. More pedestrian than Bloomies or Barney's but has frequent sales. Worth a visit if only for a look at its famous 'Santa Land'. Also worth a look-in is swanky Saks Fifth Avenue (Fifth Avenue at East 50th Street). If you can't afford the designer outfits, buy a pack of their plain white T-shirts for around US$15. For a caffeine stop, head for the peace of The Tea Box, in the Japanese department store Takashimaya (Fifth Avenue at East 34th Street). Relax over a pot of green tea and a plate of butter cookies.