What are OTKs, you ask? Over-the-knee boots. And if you follow fashion even a little, you know that OTKs, or thigh high boots, are having a moment.

This is no small trend. Shop for OTKs online and not just designer shoe companies pop up (Christian Louboutin, Jimmy Choo, Sigerson Morrison, Stuart Weitzman and Sergio Rossi have some of the best versions). More than 300 brands have gotten in on the action, including denim labels like 7 For All Mankind and Lucky Brand Jeans.

Clearly, designers are ready to cash on what they're betting will be a big, big trend this fall. But this week, I talked wto noted trend expert Tom Julian who's currently flying around the country promoting his book Nordstrom Guide to Men's Style. He's been speaking to random shoppers-both men and women-and all say they will buy items that have a longer lifespan than just one season. Whether or not OTKs fit the bill remains to be seen.

OTKs present another problem, too. Because of their close association with the world's oldest profession, pulling the look off can be downright, ahem, tricky.

Here's how the designers think you should do it: Miuccia Prada paired high-high leather waders with tweed short shorts and heavy sweaters. Hussein Chalayan added garters (pictured above) to his high-heeled versions, then presented them with short dresses and tailored boyfriend jackets. Louis Vuitton balanced his tough-girl versions with nothing but flounce-ruffles, balloon dresses and draped skirts.

At New York fashion week, several trendsetters took their shiny new OTKs out for a spin. Most, like Halle Berry on Jay Leno a few nights ago, chose to pair the boots with a super short dress. It was sexy, but was it chic? What do you think?

Here's my take: As long as you meet head-on the sexiness of an OTK with something NOT sexy, you'll wipe out even the tiniest whiff of stripper. For example, the sexier the dress, the flatter the boot should be. Got a killer pair of OTKs with a stilleto heel? Rock the look with a boxy boyfriend blazer or slouchy sweater. Julian says that when it comes to knitwear, the cardigan is the new layering sweater and works best in luxe fabrics like merino wool and fine gauge cashmere. Works for me.