I usually see the city's fashion when I'm actually there but you can capture the picture from their edition of the Elle magazine, and definitely the serbian models around the world.
Also their fashion designers are influencing the world fashion scene, just look at Roksanda Ilincic. Born in Belgrade, she started studying applied arts at the Belgrade university and continued her studies in London. Nowadays, her designs are worn by high profile clients, and are taking place next to the worlds greatest fashion designs.
Another notable person in the fashion world, serbian born, is Rushka Bergman. She is a co editor at L'Uomo Vogue and Vogue Italia and was the personal stylist of Michael Jackson.
Georgina Stojiljkovic was featured in the 2010 Pirelli calendar photographed by Terry Richardson as well as doing runways for many designers including Bottega Veneta, Dolce & Gabbana, Hermes, Lanvin, Prada, Versace and many more.
Not to mention the male models ;)
Djordje Bogdanovic
Georgina Stojiljkovic for Pirelli
Make sure not to miss the coffeplaces and clubs by the rivers