A look from Tibi Fall-Winter 2009 collection. Photo: Frazer Harrison/GettyImages for IMG

Baby, it may be cold outside, but toss on a great scarf, and, instantly, your outfit - winter coat and all - will heat right up.

"Scarves are popular because they can be functional and very fashionable at once," says celebrity stylist Mariel Haenn who has worked with Rihanna, Jada Pinkett Smith, and Ciara. "You can throw on a simple outfit in the morning and instantly make it more interesting with a cool scarf."

Whether you opt for one that's chunky and knit, long and skinny or gauzy and light, there are tons of ways to tie them to suit most every occasion.

"The trendiest way to tie them is just messily wrapping them around your neck," Haenn says. "Another great way is to just fold the scarf in half and wrap it around your neck then pull the other end through the loop and loosen it a bit so it doesn't look too proper. Right now, a big trend in scarves is the scarf that is just a loop -- so it looks like a scarf when on, but it's really a neck piece that creates volume and warmth without the hassle of tying it at all."

Not sure how to wear your favorite scarf? Wrap your head – and neck -- around these stylish tips:

What details should I look for in a scarf?
  • Haenn says it's all about personal preference. "Bigger scarves make more of a statement than a small scarf you just tie around your neck. I look for scarves with an interesting pattern or detail on the ends."
  • "Go with what looks best for your skin tone and your body shape," says Denver-based image consultant Milena Joy. "Plum, gray and chartreuse are popular colors this winter. However, not everyone looks good in chartreuse, but almost everyone looks good in navy. Smaller-framed people have a harder time pulling off bigger, oversized scarves and vice versa."

What do I do with my scarf once I'm inside?
  • "It's fine to wear scarves indoors ...whatever you feel," Haenn says.
  • As long as the scarf is your outfit's standout piece, leave it on. "Your shirt is just the canvas, especially if you have a really unique tie style that deserves attention," says Joy. "One of my favorite looks is my black ribbed tank with a long, skinny navy scarf wrapped around my neck twice and double knotted to an angle. It is simple, yet chic."

What are the coolest current styles?
  • Haenn recommends looking for anything graphic. "Or a really nice cashmere scarf is always a good investment," she says. "Alexander McQueen, Chloe Sevigny for Opening Ceremony and Acne have created some great scarves."
  • "I love scarves with texture," Joy says. "Keep the color neutral or muted and let the texture stand on its own. You don't have to be a scarf-tying genius to wear these styles because the texture adds enough interest, so you can keep the tie simple."

What's the trendiest way to tie?
  • "Try an infinity scarf which is essentially just a continuous loop of material," Joy says. "Depending on the length and weight of the material, you can wrap it around your neck once or twice and you're done."
  • If you do want to tie it, Joy suggests wrapping it around your neck once and then tying the ends in a knot over and over again: "It creates a braided rope look," she says. "Tuck the ends in for a clean finish to the end of the rope."