Just take some 'brave' pills and get out there! It takes a bit of time to get over your self conscious conspiciousy, but once that hurdle is passed you'll be able to develop your own style. Look for interesting light, interesting scenes, get in close, and when you think you are close enough, get in closer!
A less conspicuous camera helps here rather than a large DSLR, and if you feel threatened or intimated, move off somewhere where you feel less so. Watch out for private land v public land, a lot of shopping centres are private land, so just beware.