Easy, stay away from the shower for about four weeks, sleep in your closes, keep the same clothes on for four weeks as well and pack your stuff in something like this and you'll be perfectly safe.
Everything else is just fooling yourself.
Pay attention to your surroundings, use a bag that closes with a non-simple mechanism and don't dress like a complete dork and you are about as safe as all the other tourists that will roam the same streets.
Just one thing: it's not the bag that attracts attention, it's YOU.