Itsy-bitsy bikinis were practically second skin for the former star of The Hills and Laguna Beach, but Cavallari tells PEOPLE, "[It] wasn't until I moved to L.A. – with all the paparazzi – that I became really aware of how I looked." So how does the recently engaged star (to Chicago Bears quarterback Jay Cutler), 24, get the body confidence to rock a two-piece and deal with cameras 24/7? "Everyone is their own worst critic," says Cavallari, who plays up her favorite feature – her legs! – with string bikinis. "Sometimes you just have to take a step back and say, 'Okay, it's actually not that bad.'"