A major factor in the success of premium denim has been its ability to spark trends -- big ideas in silhouettes and washes that eventually trickle down to the mass retailers of the world.

Still, some L.A. retailers say there aren't enough imaginative ideas surfacing within the category. Fraser Ross, owner of the Kitson stores, said the big premium brands tend to copy each other -- resulting in a glut of the same styles. "Everyone did the ripped, bleached and tie-dye thing for fall," he said.

For fall, and even spring 2010, most of L.A.'s premium players are pushing the same two silhouettes: the ubiquitous skinny jean and the low-slung baggy (often rolled) boyfriend-fit jean that debuted a few seasons ago.

"What we've seen is skinny become mass now," said Marc Crossman of Joe's Jeans, adding that the brand's boyfriend jean will be slimmed down slightly for fall.

At J Brand, the skinny is losing weight. "There's a real turn toward [denim] leggings in the industry -- having a super-sleek silhouette," said Susie Crippen, co-founder and creative director, who designed a stretchy jeans legging for fall in a super lightweight denim with a 10-inch leg opening.

"Skinnies are still so strong," said Colin Dyne, president and chief executive officer of premium denim and sportswear brand William Rast. "And the men's business has turned into a straight-leg business [as opposed to boot-cut.]"

The brand, co-founded by Justin Timberlake, will lengthen the rise on women's skinnies -- making them slightly more body-friendly -- and is experimenting with metal studding and other low-key embellishments for fall and holiday.

"Skinny, for us, will always be who we are," said Michael Ball of Rock & Republic. "I'm not really into the whole baggy thing."

Skinny styles remain red-hot in urban markets despite the fact that they flatter only a small segment of the population. Look inside any American high school and you'll see bodies of all sizes stuffed into stretch-denim skinny jeans.

In L.A. -- a city awash in willowy physiques -- the narrow silhouette is rivaled only by the boyfriend.

L.A.-based TV writer Shawn Simmons, who wears straight-leg Levi's exclusively, said he has "no idea what premium denim is," but added that his wife, Christine, buys skinny and boyfriend jeans from Barneys New York (which largely stocks premium brands). The couple buys denim for their 2-year-old son, Flynn, at Lucky Brand, where kids' jeans can range up to $69, but are often on sale for half that.

Premium denim fan Michelle Dalton Tyree, founder and president of L.A. public relations firm Blab Communications, wears skinny J Brand jeans religiously, though this summer she's been mixing the fitted pant with boyfriend-fit jeans from Current/Elliott, "which get 'oohs' from other women, but snickers from the older crowd who shake their heads in confusion about how much I've paid [around $230] to have holes in my jeans," she said.

But Tyree isn't about to invest heavily in pricey kids' jeans for her 6-year-old daughter Layla -- she scours mid-priced stores including the Gap for cute styles.

"Layla recently fell in love with a very hip little pair of jeans at Oilily and I splurged because they were funky, cool and, yes, on sale," she said. "As much as I love fashion, I can't bring myself to spend $140 on a pair of jeans for a 6-year-old."