LOS ANGELES — Though he calls it “T-shirt dressing,” newcomer Rami Kashou’s definition is clearly a cut above the conventional notion of the look. Working with jersey in everything from silk and wool to rayon and cotton, the 26-year-old designer braided, pleated, ruched and fringed the stuff. And the polished, sensual results were a highlight of the city’s fledgling fashion week, which comes to a close tonight. Here, his ribbed and wrapped cotton and rayon top and fringed wool gauchos. For more on the fall season, see pages 4, 5, 8 and 9.