There are only 10 days left until 2009 disappears into the ether of history and 2010 is upon us, so without any further ado, here is the final installment in my series of posts on the biggest trends of the year. Today, we will cover the most notable nail fad of ‘09, the wild hair trend sparked by a certain Gossip Girl, and the fashion trick that’s fit for a First Lady.

BEAUTY: Matte nail polish. This was, hands down, the biggest nail trend of ‘09 - and one of the biggest beauty trends of the year, period. After matte-centric ManGlaze and KO Knock Out made headlines early on with their unique colors and finishes, it seemed like every single polish company (OPI, Zoya, Nubar and Orly leap to mind) launched at least one collection of matte polishes this year - and, in many cases, several. Essie, China Glaze and Rescue Beauty Lounge took the craze one step further with by creating matte top coats, which can be brushed onto any shade to create that velvety matte look. I haven’t seen many low-end knockoffs of the matte nails craze yet - you still have to stop by a beauty supply store or specialty retailer like Ulta to stock up - but I predict that drugstore brands will be rolling out their take on the trend very soon. Something to look forward to in 2010 - unless you’re already burnt out on it, that is! So what was your take on matte polish? Did you dig it, or do you prefer your manicure shiny?

HAIR: Long, untamed tresses. If you’re wondering what the most popular hairstyle of 2009 was, then look no further than Blake Lively. The blonde bombshell, best known for her portrayal of Serena van der Woodsen on Gossip Girl, epitomized the wild, messy, borderline unkempt long hair that could be seen on countless Hollywood starlets this year. (Case in point: Check out my last Latest Trends post, in which Lindsay Lohan is shown rocking the look.) I would describe it as Brigitte Bardot meets a serious case of bedhead. The New York Times even likens it to “the ‘Rachel’” of the ’00s - in other words, the defining women’s hairstyle of the decade, just as Jennifer Aniston’s updated Friends shag was the ‘do of the ’90s. And if you lack the natural length necessary, don’t fret - there’s always extensions!

FASHION: Waist-accentuating belts. This is one of the most figure-flattering fashion trends in recent memory, and it is my humble opinion that we owe it all to First Lady Michelle Obama. Sure, women wore belts before Mrs. O emerged as a fashion icon, but I can’t remember so many ladies belting their dresses, cardigans, and so forth quite as much as they do now. The belt has evolved from a sartorial afterthought to one of the most vital accessories a woman can own. They can make an ill-fitting or loose dress incredibly pretty and polished, and they make any outfit look “done,” but not stuffy. If you don’t have at least one or two belts at this point - which I doubt - look for a wide one that’s fitted to your waist but has a bit of stretch, and consider an eye-catching color for added drama. Or you could go the First Lady route and pick up a clear belt, like this one. It’s sleek and futuristic yet pretty and classic, and it will certainly go well with any color combination. Belts, we salute you. Thank you for bringing the hourglass figure back into popular consciousness!