From PEOPLE Magazine Click to enlarge
Navigating a showbiz career for two decades is hard enough—but looking fabulous throughout? "This is a real achievement, because everything is working against us as we age," says How Not to Look Old author Charla Krupp. Icons like Madonna, Halle Berry, Faith Hill and Jennifer Aniston "not only look as good as they used to—they look better," says Krupp. So how do they do it? Krupp says stars like these use the march of time to their advantage. "It takes a while to develop a sophisticated eye. Just because you're a great singer or you can act doesn't mean you know what looks good on you. They've all developed a discerning eye about what works, and all have become more brutal about not leaving the house unless they look fantastic. They've learned." Here, a look back at those style lessons.

Halle BERRY
She played down her beauty to nab an Oscar for Monster's Ball—but turned it up to be a red carpet winner

1989 AGE 23
"I look back at my pageant days," Berry said in 2006, "and it's, 'Oh my God, what was I thinking?' "

1995 AGE 28
"I was a slave to lavender," she told INSTYLE in '07. "Lavender eye shadow, lavender shoes, lavender lipstick—woof!"

2002 AGE 35
"Ladylike and elegant," said designer Elie Saab of Berry when she wore his gown to pick up her 2002 Best Actress Oscar.

2005 AGE 39
Facing 40 didn't faze Berry, who later said, "I felt I had the right to be who I wanted to be."

Now! AGE 42
While pregnant with daughter Nahla, Berry said, "My skin is aglow from all the hormones!" Six months later she showed off her figure at a September bash.

Jennifer ANISTON
That hair! That body! After Friends—and a very public divorce—the yoga-loving actress remains the picture of serenity

1995 AGE 26
The focus on her Friends 'do led her to ask, "God, I wonder if I'm a good actor? Can they see past my hairstyle?"

1999 AGE 30
The self-described "one-outfit girl" told INSTYLE she felt pressure, as a rising star, "to get better taste."

2005 AGE 36
"We have such resilience," Aniston, looking radiant after her breakup from Brad Pitt, later told Good Housekeeping.

Now! AGE 39
"She has a great body and shows it off—but doesn't overdo it," Krupp says of Aniston. "She's understated, elegant."

Faith HILL
Though she claims to hate makeup, she went from country to couture—and hasn't looked back

1994 AGE 27
"I am a country girl. Anybody who really knows me will tell you that," the Mississippi native has said.

2001 AGE 33
As fans debated her short 'do, husband Tim McGraw said, "She could shave her hair off and still look great."

2005 AGE 37
Her style philosophy? "I'm constantly wanting to knock my husband off his feet," Hill told PEOPLE.

Now! AGE 41
"She's not just a girl from Nashville anymore," Krupp says of Hill (in Valentino). "She's aware of fashion."

Queen LATIFAH
From Jersey-girl tough to all-out glam, the rapper-actress continues to surprise with her winning style

1992 AGE 21
"When I started I was really socially conscious, so I wore African garb," Latifah (born Dana Owens) has said.

1994 AGE 24
"When I was doing Living Single, there was pressure to lose weight," Latifah said. "But I am a big, confident girl."

2003 AGE 32
Stylist Susan Moses (who did this look) says, "I tried to show her feminine side—and the side that loves motorcycles."

Now! AGE 38
"The Grecian gowns, the long hair—she's shown that just because you're a size 12 or 14 doesn't mean you can't be sexy," says Krupp.

Angelina JOLIE
She's always been sexy. But now the globe-hopping mother of six has embraced a softer, more sophisticated look

1998 AGE 23
Jolie won a Golden Globe dressed by Giorgio Armani, who called her "one of Hollywood's most elegant and graceful ambassadors."

2001 AGE 26
Married to Billy Bob Thornton—whose blood she kept in a vial worn around her neck—she was, says Krupp, "edgy, very Goth."

2006 AGE 31
"I want my wardrobe to be beautiful, sexy and comfortable," said Jolie the mom (in Reem Acra).

Now! AGE 33
Told that she and Brad Pitt are two of the best-looking people alive, Jolie responded, "Our kids think we're the dorkiest people on the planet."

MADONNA
At 50 and a mom of three, pop's greatest—and fittest—chameleon says, "I've discovered things I had no idea of when I was in my 20s"

1984 AGE 26
"I was born to flirt," the new star quipped to PEOPLE as young Madonna wannabes picked up her Boy-Toy style.

1995 AGE 37
"I think she gets bored easily," says Krupp of Madonna, who still sported peekaboo underwear in her mid-30s.

2003 AGE 45
"I don't want people to dress like me anymore," Madonna said in her 40s. "Now I want them to think like me."

Now! AGE 50
"I think you have to try on a lot of guises before you know who you are," Madonna told INSTYLE.

JENNIFER LOPEZ

1996 AGE 27
Growing up, "I looked like a girl from the Bronx," Lopez has said. "A lot of eyeliner and a lot of curly hair."

Now! AGE 39
"She knows how to dress her body," says Krupp. "Everybody loves that she's not a size 0."

DREW BARRYMORE

1987 AGE 12
Once, after a bad perm, "I never cried so hard in my life," said the E.T. child star.

Now! AGE 33
"If I'm good to myself," she has said, "I feel beautiful inside—that shows."

CELINE DION

1993 AGE 25
"In my early videos, my look is terrible," Dion told INSTYLE. "I can't believe my hair."

Now! AGE 40
Dion still loves "a fitted dress," she says. "And my husband [René Angélil] does, as well."