KATHERINE HEIGL
"She loves that retro feel," says the star's hairstylist Sean Flanigan. "We did a little nod to Marilyn with a tousled blond curl."

AMY ADAMS
"It's a modern take on a very classic silhouette," says Matrix stylist Mark Townsend of Adams's sculpted waves. "I wanted to keep it very young."

Penélope Cruz
"I wanted her to have hair that was simple chic," says Pantene stylist Danilo, who created a "healthy, abundant and clean" look for the star.

HEIDI KLUM
To get her sleek Grace Kelly look—complete with oversize bun—"it took about four to five hours and a small village," says Klum.