You know a shopping district is popular when it requires an NYPD officer for crowd control. Horns from yellow taxis blare on Fifth Avenue as journeys across the city are stalled by hordes of shoppers crossing sidewalks, directed by whistle trills and white glove commands.

In the last five years, the shopping scene here has changed dramatically.

Concept stores have sprung up, fusing fashion with rooftop hangouts and even flower shops. Once home to only expensive designer labels, Fifth Avenue is now peppered with high street chains such as H&M and Banana Republic, while, conversely, hip downtown now houses catwalk giants, such as the newly opened Celine store.

Upscale and affordable have merged. For the shopper, that means a more varied retail playground.

In my favourite shopping district of SoHo, high end labels exist discreetly; I dip in and out of cool, loft spaces with barely-there shop signs.

Even the street market stalls have an upmarket feel, selling rose gold jewellery and one-off arty prints.

Hypnotised by a window display of shoes, I wander into Barneys on Wooster Street, one of four Barneys department stores in New York selling high-end style in an unstuffy, urban setting with white walls and concrete floors.

I stroke the Alexander Wang bags as if they were kittens and a shop assistant swoops to my arm candy aid.

“Oh, you’re British,” he quickly observes.

“The Brits just love Alexander Wang and 3.1 Phillip Lim bags... It’s a big saving,” he says in a hushed tone, before pointing to the store’s best-selling Pashli satchel.It’s a snip at 895 US dollars (£560) – I spy the very same bag for £740 in Selfridges.

Undoubtedly one of the biggest attractions of shopping in New York is hunting down the same US brands for a fraction of the price that you might find them at home – made even more appealing by a favourable exchange rate.

One of my shopping pals raves about the savings she’s stacked up at J.Crew after she tots up how much the shirt and earrings she’s just purchased would have cost her in the UK... and then buys more with the difference!

We dash from one shopping district to the next, using the city’s neat grid system to navigate our way. The moment I’m in midtown, it’s virtually impossible to lose sight of my landmark hotel on the edge of leafy Central Park.

The new Park Hyatt occupies the first 25 floors of the skyline-dominating 90-storey One57 building. Rooms have floor-to-ceiling windows, allowing you to soak up the buzz of midtown from a height.

For technophiles, remote controls bring down screens at dusk and switch on a hidden television in the bathroom mirror so you can apply your mascara with one eye on Carrie Bradshaw's Sex And The City exploits.

All shopped out, I retreat to the impossibly luxurious Spa Nalai on the 25th floor. I take a scenic yoga class overlooking the skyscrapers and yellow taxis, swim in the heated pool piped with underwater music from Carnegie Hall, and sip from Park Hyatt New York branded water bottles in the hydrotherapy hot tub.

To bring me back down to earth post-shopping high, I experience the spa’s signature treatment – a massage on a warm, sand quartz bed that’s said to ground the body.

“Ooh,” my massage therapist remarks kneading my knots.

“Your arms and shoulders feel very tight. Have you been carrying a lot of bags?”

My shopping addiction rumbled at the massage table! Now that’s a first...

Where to shop

Saks Fifth Avenue, 611 5th Avenue

Currently enjoying a major retail revival, Saks is ‘dreaming big’ for holiday season. Expect elaborate window displays, thousands of twinkling lights and a hyperluxe gift section. 60,000 dollar Chanel watch, anyone? saksfifthavenue.com

MoMa Design Store, 44 West 53rd Street
Directly opposite the MoMa Museum, this is like a playroom for adults, packed with quirky design objects, jewellery and gifts. It’s the ideal hunting ground for the person who has everything. momastore.org

Story, 144 10th Avenue
This retail space ‘changes like a gallery and sells things like a store’. It’s an ever-evolving pop-up for new retail concepts and the latest installation opened on November 5.
thisisstory.com

Where to eat

ABC Kitchen, 35 East 18th Street
Fuel a full-on shopping day with lunch or brunch at Michelin-starred chef Jean-Georges Vongerichten’s popular hangout. The farm-to-table movement guarantees fresh menus that diversify to feature seasonal produce. Three course lunch menu: 32 US dollars. abchome.com/eat/abc-kitchen

BG Restaurant, 5th Avenue 58th Street
For a more formal ladies-who-lunch setting with sweeping views of Central Park, book in at Bergdorf Goodman’s restaurant. Head to the seventh floor of the department store to sip on Sheer Glamour champagne cocktails and try the Gotham salad speciality. Main approximately 30 US dollars. bergdorfgoodman.com

Lisa Haynes was a guest of the 5* Park Hyatt New York (parkhyattnewyork.com; +1 646 774 1234) where rooms start from 795 US dollars (two sharing), excluding breakfast and VAT.
British Airways (ba.com; 0844 493 0758) offers three nights at the 5* Park Hyatt New York, from £1,499 per person, travelling November 1-December 18, 2014. Includes return flights from Heathrow.