What Makes Julia Roberts Most Beautiful – Still!

When you're the World's Most Beautiful Woman, there are a few things to always remember before leaving the house: Brush your teeth. Don't take longer than the kids to get ready. And leave certain things (hair color and waxing) to trained professionals. Or so says Julia Roberts in an exclusive Q & A to celebrate her fourth turn as the cover girl for People Magazine's Most Beautiful issue.

Though it's hard to believe it's been 20 years since Roberts starred in Pretty Woman, her relaxed vibe about beauty has served her well over the years. "She's never looked more beautiful," says Ryan Murphy, the director of her upcoming film, Eat, Pray, Love, based on the huge bestseller. "She is so happy and fulfilled and it shows."

At 42, the mom of three (twins Hazel and Phinnaeus are 5 and Henry is 2) signed her first beauty contract in January to become Lancome's global ambassador. "It's fun to find myself with this type of new career at my advanced age!" she writes about the gig, in the issue on newsstands Friday.

While Roberts still wows on her rare red-carpet appearances, her beauty team reveals that it never takes more than two hours to get her ready – even for the Oscars. "There is nothing contrived," says her longtime hairdresser Serge Normant. "She believes you have to be comfortable – you have to have a good time."

Still, she does have a few beauty tricks up her sleeve. According to Genevieve, her makeup artist, Roberts uses a moisturizing tint (no heavy foundation – ever), followed by a creamy blush. "Her skin is amazing," says Genevieve. Then comes Roberts's fave part: eyeliner – smudged and sexy. "It's something she can't live without," notes Genevieve. Two coats of mascara, followed by a natural sexy lip "not too shiny" and she can put those 20-something starlets to shame.

But, at home, Roberts favors a more relaxed look: makeup-free and often in yoga pants. It's all part of her easy home life that she's embraced since marrying cameraman Danny Moder, 41. "She seems to have made peace with everything," says Pretty Woman director Garry Marshall, a longtime pal. "He is a laid-back guy. Surfing is his big thing. He's not a driving ambitious husband. They kind of enjoy being with each other without a big circus." And the kids? "They are very cute and have a great joie de vivre, which Julia always had," he says.

Even her old pal George Clooney agrees she's as beautiful inside as out. "There's a reason why Julia is a timeless beauty, and it has nothing to do with the way she looks," he says. "It has everything to do with who she is."

So who else has been selected by People as "Most Beautiful"? Well, you will have to pick-up this Friday's edition of People for details.