See what looks are sizzling -- and fizzling -- on the red carpet!

Angela Weiss/Getty (2); Jon Kopaloff/FilmMagic

In our weekly roundup of the looks that are gaining fashion ground (and the ones losing their style street cred), we saw serpentine style, crisp collars and a neckline that’s just not picking up steam.

Up: Snakeskin. This look has been slithering its way onto the red carpet these past couple weeks, and our leading ladies are finding many different approaches to wearing the material. Nikki Reed (left) sports a cream sheath embossed in the glam print. Amy Adams also steps out in the style (literally) with a pair of nude python Christian Louboutin pumps while Kate Hudson wears an snakeprint white leather mini. Ashley Greene put our black skinnies to shame in her leather RTA ones – which were also, of course, on-trend.

Up: Collared Dresses. If you frequent our Last Night’s Look gallery, you’re well aware that the stars love menswear inspired fashion. This week, these looks caught our eye. Diane Kruger (center) coordinates with rumored fiancé Joshua Jackson in a gray collared dress. Nikki Reed not only modeled the snakeskin trend but this one as well — her stylist must own a crystal ball. Eva Mendes rocks the style in her polka dot shift while Kate Mara opts for a Peter Pan collar instead of the traditional pointed tips.

Down: Super-high Necklines. With spring right around the corner (we hope), it’s nearly time to put away the turtlenecks and flaunt a little décolletage. Though we love this embellished version on Eva Longoria, we’re betting fewer people will be covering up on the red carpet in coming weeks. Though it could still pop up here or there — we had a big debate over it in our Oscars gown prediction video — we don’t think the stars want to be stifling on the red carpet.

–John Soper