Heidi Klum explains why wearing lingerie is essential and other ways she practices self-care

— -- Heidi Klum has a secret for looking that good, she told ABC News while driving to film an appearance on "The Ellen DeGeneres Show" earlier this week.

It's lingerie.

"It makes our body look better, but you also feel it," she said. "Your body just looks better, your shape ... just looks better wearing the right pieces.

"We buy beautiful lingerie to show it to others, but first and foremost we do it for ourselves. It enhances our self-esteem," Klum, 44, added.

It doesn't hurt that the former supermodel has her own lingerie collection -- Heidi Klum Intimates. Klum teamed up with "Project Runway," the fashion competition she's hosted since 2004, where contestants had to design a look for her collection on its Sept. 7 episode.

Designer Michael Brambila won the competition with his pale pink art deco-inspired camisole dress.

"I just loved the color that he chose," Klum gushed. "I loved the neckline and it is a great silhouette for different kinds of body shapes."

That detail was important for the Emmy-nominated "Project Runway" host who wanted to "cater to all women of all different sizes," she said.

Klum's role on "Project Runway" gave her the confidence to show for the first time at New York Fashion Week. She debuted an 84-piece collection, "Esmara by Heidi Klum: Heidi & The City" in collaboration with the German box store Lidi last week.

It's hard to imagine that along with her fashion lines, Klum is also a judge on "America's Got Talent" and raising four children from previous relationships.

"I'm definitely someone who schedules. We all work on the iCal and everyone has a different color," she said, referencing Apple's Calendar app. "I’m green [and] my kids are blue ... so it’s easier for everyone to see and understand."

Klum continued, "I’m just a working mom like other women are working moms, but I’m in the public eye so people think I’m busier. But ... we all have to juggle as best as we can."

It's important for the former supermodel to practice self-care in between juggling.

"I actually have a room in my house -- because I renovated my house before we moved in -- and I dedicated one whole room to myself. There’s the biggest bathtub I could possibly find in the world," Klum detailed. "I love taking long baths. It’s good the soul and for the body and for my bones and or my skin.

"I have beautiful shelves and pretty things in there that I’ve collected from all over you know," she continued, "like Buddha, beautiful smelling candles, lavender soaps, Epson salts and different kind of things."