Oscar Hot List: Hippest, Hottest Trends in Hollywood

From the must-have jewelry to the "it" shoe, Oscar season is the time when some of the hottest trends of the year are born.

Nothing says you've arrived in Hollywood like a Rolls-Royce. It's already a favorite of newcomer and "Dreamgirls" star Jennifer Hudson, and for celebrities driving to the big show, a customized car is the only way to ride.

The "Dreamgirls" cardio dance class at Crunch is inspired by the eight-time nominated movie. It's the newest workout in town and incorporates kicks and even a boa.

"It's about being a diva and performing and definitely about having attitude," the class instructor, Stephanie Reed, told "Good Morning America."

To kick up those legs, you need glamorous heels. Everyone from Oscar nominee Kate Winslet to Queen Latifah has donned Stuart Weitzman's shoes. His line has nearly every style you can imagine, including the latest peep-toe pumps and Swarovski crystal-encrusted sandals.

Even if you're not walking down the red carpet any time soon, for the best shoe fit, experts suggest you try on shoes at the end of the day when your feet are at their most swollen.

For a treat to keep themselves sleek, celebs love Pinkberry frozen yogurt. The 25-calorie-an-ounce dessert is rumored to be a favorite of Kirsten Dunst and Leonardo DiCaprio.

Oscar weekend isn't complete without diamonds in earrings, bracelets, necklaces and rings. The hometown favorite for sparkling gems is Los Angeles jeweler Martin Katz.

Katz outfitted Felicity Huffman with her jewels at last year's Oscars.

Huffman isn't the only fan. Leading ladies like Nicole Kidman, Uma Thurman, Salma Hayek, Sarah Jessica Parker and this year's Oscar host, Ellen DeGeneres, have worn Katz's diamonds.

But do the stars ever want to keep them?

"They always want to keep them. One year, I offered to trade Emma Thompson her Oscar with the earrings she was wearing," Katz said. "She wouldn't make the trade."

For the truly trendy, this year's must-visit temple of fashion is Lisa Kline, a Beverly Hills boutique where customers might even spot one of their favorite fashionistas.

"You can always run into Lindsay Lohan, Paula Abdul, Jennifer Garner. … Penelope Cruz, Halle Berry," Kline said.

According to Kline, the biggest fashion trend to watch for is the jumpsuit.

"You have to try it on," she said. "It's totally sexy with heels or flats, tons of jewelry; it's hot. It's a hot look."

Celebs who want to look their best can try the "Oscar Gold" package at Le Spa at Sofitel in Los Angeles. The package includes the lift and firm facial, a "liquid gold" bath, and a body treatment that leaves your skin satiny soft.