When you photograph people in other countries, it's wonderful to capture serendipitous moments that are completely natural and unposed. But so often there are other elements in the scene that hurt a particular composition, such as distracting backgrounds, bad shadows, harsh light, trash on the ground, and so on. The way I address this issue is to preconceive what i'd like to capture, and then I set it up. That means, though, that I have to become the director.
You can do the same thing. For example, in the portrait above of a Buddhist monk in Burma, I asked the young boy (through an interpreter) to look out of the doorway as if he were looking for a friend. I closed the right hand door to show the carving, and then I spread the boy's fingers and told him where to place his foot. In this way, I was a director and I was therefore able to capture exactly what I wanted.
In most cases, the people you photograph don't know how to pose well, they have no idea what you see your mind's eye, and they are not aware of iight as it pertains to good picture taking. This is where you, as the director, have to take the lead and direct your subjects so you get the best shots -- all the while being as sensitive as possible to the culture and to your subject.