Taylor SwiftTaylor Swift graces the cover of the December issue of InStyle magazine, giving readers an inside look into her life out of the spotlight, and offering some of the fashion advice that has worked best for her.

The statuesque superstar, who stands 5-foot-11, knows a thing or two about how to best dress for her height, saying she personally has to keep an eye on the length of her dresses because "dresses made for regular heights can look like a shirt on tall girls." She advises other girls to not being afraid of wearing heels, revealing, "I went through a phase where I wouldn't wear them because I felt like a giant giraffe." And when it comes to carrying oneself, Taylor advises, "walk like a model -- throw your shoulders back at all times!"

As Taylor approaches her 20th birthday, on Dec. 13, she reflects on her fashion style throughout the past four years as her country-music career blossomed. "I've never been one to change dramatically, but I definitely have changed since I was 16."

These days, Taylor, whose signature look has included sundresses and cowboy boots, has glammed things up a bit. She's rarely seen without some kind of sparkle to match her twinkling blue eyes.

"I like how fairies look with little dresses," she says. "I like sparkles and glitter!"

In addition, she finds herself mirroring the look of another iconic woman, former first lady Jacqueline Kennedy Onassis. "I'm inspired by how people dressed in the '60s, and that beautiful, feminine energy of Jackie O."

Check out Taylor's many looks in her music videos, airing now on her own on-demand channel from Comcast.