I wouldn´t write about this, except I see a need for it . . . so here we go, travelers!
Be aware! I can´t tell you how many tourists I spy here in the Andes of Peru who are completely, utterly and totally unaware of themselves and their packages, backpacks and purses. Really, I promise I will find at least one tourist today while I´m in Cusco who is oblivious and I´ll take a picture. Click here for an example of how not to be. When you travel, you must be aware. Without a sense of awareness, the truth is that you´re a target for thieves.
Got a great camera and lens? That´s awesome. Make sure you don´t flaunt it around. People living in high-tourist areas often do not have the resources to buy a camera like yours. If you must sport it around your neck, do something to disguise it. I suggest slinging the stap over your shoulder crossways and push the camera to the side of your body. Then put on your sweater or jacket. The camera will be easily accessible, yet less visible between the folds of your clothing. Make sure you know how to use your camera before leaving home. I see many, many photographers with a furrowed brow who are too busy trying to figure out their settings and are unaware of what is going on around them.
Um, wear your money belt under your clothes. Yes, I still see people tromping around with their money belt latched around their waists, on top of their clothing. If your money belt is visible, you are asking for trouble.
Walk around with a sense of awareness. Thieves are only looking for the easiest of pickings. If you are walking around loudly talking to your friends, camera out, while chomping a croissant, hands full and carting around a huge pack with lots of stuff dangling from it and completely unaware of the persons in the crowded street who are next to you, then you are once again asking for trouble. Besides, those people are just downright annoying to everyone, locals and other travelers alike.
Check out the sights. Be unobtrusive in the country where you are a guest. I would say try not to wear khaki shorts at all costs, but that´s just me . . .