Victoria Beckham takes to the field and The Fashion Games play on.

During the spring collections, Victoria Beckham took in the Polyphonic Spree at Oscar de la Renta, endured the two-hour wait at Marc Jacobs, watched models stride by a giant bow installation at Chanel and fawned over the naughty nurses at Louis Vuitton. Britain’s top fashion expat, now happily ensconced in Beverly Hills with her soccer-star husband, David, and their kids, Brooklyn, Romeo and Cruz, is clearly not a novice when it comes to fashion shows. Whether it’s New York, Paris or Milan, Beckham will trek to the edge of the city, fight her way to her seat and refuse to crack a smile for hordes of photographers desperate to get that winning shot.

Beckham is quickly becoming a part of the fashion firmament. Not only does she cheer on her favorite designers from the front row, she also manages her own lifestyle brand, dVb, which launched earlier this year with jeans and sunglasses, and now hopes to turn herself into a style guru with her own how-to guide, That Extra Half an Inch: Hair, Heels and Everything in Between, just published Stateside by Harper Entertainment.

“I love fashion and have been in a position where I have worked with the best hairdressers, makeup artists and designers in the world, and I wanted to share that,” explains Beckham, whose career as the Spice Girls’ Posh catapulted her into the spotlight more than a decade ago. “You don’t have to wear top-to-toe designer clothes. I wanted to give people tips on where to shop on the high street, or where to get that perfect pair of jeans according to your body shape. It’s everything that you need to know about style.”

Indeed, That Extra Half an Inch is aimed at women of all ages, shapes and budgets. It’s filled with Beckham quips-cum–fashion and lifestyle tips, from putting on the right stilettos to what to wear on ski slopes. “I am a girls’ girl, I am not the kind of girl that men put pictures up of on their wall, and this is a girls’ girl book,” she adds. “I am a real consumer, I know how girls want to look and feel.”

Beckham cites her mother, to whom the book is dedicated, for giving her the most memorable fashion tips, even though she chose to be a rebel of a daughter herself. “My mum gave me two pieces of fashion advice: Don’t eat beetroot because it stains, and don’t wear sideways stripes because they are unflattering,” she recalls. “For years, I wouldn’t go near sideways stripes. And then a few seasons ago, I thought, you know what, I love sideways stripes. I actually wore them on the cover of the American version of the book, and put in a little disclaimer to my mum, saying, ‘You told me not to wear sideways stripes and now I love them.’”

From slim jeans that serve to elongate the appearance of legs to oversize sunglasses to hide an early school-run for the kids, Beckham stays true to her own fashion tips with dVb. She is building its network of stores, adding Bergdorf Goodman, Maxfield and Net-a-porter next summer. “It’s not about getting to as many shops as possible,” she says. “My image is so out there, and people read about me, especially in Europe, virtually every day,” she admits. “I have to make sure my product is only available at specific stores, because if not, it would just be overkill.”

Beckham isn’t styling her bandmates for their final world tour, which kicks off in December. That assignment went to Roberto Cavalli, who is expected to create six to seven changes for each gig.

He was their first choice, “because we needed an amazing designer who understands the Spice Girls, where we were 10 years ago, where we are now. We need glitter, we need stage costumes, and Cavalli is the king of that.”

Beckham agreed to reunite with bandmates Geri “Ginger” Halliwell, Melanie “Sporty” Chisholm, Emma “Baby” Bunton and Melanie “Scary” Brown for one reason only: “I want my children to see that mummy was a pop star,” she says.

When she’s perfectly groomed and dripping in designer clothes at all times of the day and night, some may turn their noses up at Beckham’s fashion choices, which make a prominent case for a lot of leg and even more cleavage. Yet Beckham talks about the spring 2008 runways with the ease of a true front-row veteran.

“I really liked the collections,” Beckham says. “For me, it’s always great to go to the shows….Of course I have fun….I really appreciate fashion, and I find it inspiring. I love to support key designers I know and respect.”

Her favorite for spring was Louis Vuitton, for its colors, fabrics, sequins, accessories, nurses’ outfits and a particular pair of tight tuxedo pants.

“The shoes were major,” Beckham enthuses, in one of her typical Posh-isms. “I thought it was just genius. Quite often with Louis Vuitton, I like the very simple handbags, but have never actually worn Louis Vuitton, because I find it’s just not my personal taste. But after seeing that show, there were lots of pieces that were.” That said, don’t expect to find her posing on the red carpet in one of the nurse looks that opened the show: “If I do buy the nurse’s outfit, maybe I’ll keep that one at home.”

She also raves about her first Oscar de la Renta show at a former Christian Science church on Park Avenue. “I thought it was so glamorous and sophisticated, and the fact that Oscar came out at the beginning, said hi and made sure I was happy was just incredible,” she says.

Ditto Marc Jacobs, which rocked her off her, well, bare legs. Jacobs’ show suggested a more subtle, offbeat sexuality, something that Beckham, who leans toward a va-va-voom vibe, was surprisingly taken by. “It was all about underwear and having your underwear showing,” she explains. “I think it was very sexual.”

Because she has been busy rehearsing for the Spice Girls’ farewell tour, Beckham hasn’t had much time to place her spring orders, except for a few looks here and there from her friend, Giambattista Valli. But after viewing the collections, she plans to splurge at Louis Vuitton and Marc Jacobs later on in the season.

It’s clear she enjoys every second of the fashion circus, even more so than perhaps attending a concert or cheering in a sports arena.

“I love going to soccer games because I like to go and support David, and if it’s a big, big game, it’s very exciting,” she says. “I can take the kids, and it’s something that we can do as a family. That’s a good thing about concerts and soccer games…whereas a fashion show is my work, my passion, it’s not my husband’s. I do it on my own. It’s more of a personal interest.”

Plus, there just isn’t enough fashion at those other venues. “I used to think fashion and music went hand in hand, and I think in the Nineties, they did and there was a crossover,” Beckham says. “Now, I don’t think there is very much good fashion in music at all.” There are exceptions to her rule, though. “Madonna will always be hugely important fashion-wise, and Rihanna, who I think is great, dresses well, and her videos are very styled,” she says. “Gwen Stefani is also important. She has a very strong image. But it’s not like it used to be. It’s not as close as it used to be.”

For a bona fide fashion mascot, her own fashion message is surprisingly simple. “Be realistic about who you are, your shape and your personality,” she says. “And don’t wear things too challenging. I always say, life is challenging enough, why be challenged by your clothes?”