Street photography is a form of real life people documentation process, especially taking portrait shots of random strangers encountered on the streets, and is no easy task.
It is either you grab a photograph of total randomness, capturing the feeling of awkwardness between the subject's response towards your camera pointing at them directly, or producing a completely different outcome: your subject being connected to you, with an eye contact or facial expression that engages the viewer, and speaks out strongly. It takes time for the subject to get comfortable with you, giving you a natural look and it does not just happen quickly. Sometimes, it does not happen at all.
The look in the eyes are extremely important: does your subject look at you angrily, as a threat, or a person he wants to shove that huge thorny durian he is holding into a random orifice of your body? Likewise, the facial expression or the smile tells all the stories of the person: does your subject see you as a complete stranger? Is he comfortable being around you? What is he thinking when he is looking at you and your camera?
A good example was the photograph above of a random kid I found on the street, clinging to his mother. Initially, the kid was rather shy, and hid away from me. The mother was kind enough to allow me to snap some photographs. Hence, I moved closer, and smiled. I believe I do have a good smile, because my subjects have been responding very well to my smile this far. The kid slowly warmed up to me, but still gave me that cold, curious, "who the f*** are you" kind of stare.
Soon enough, the kid let his guard down, and smiled in such an adorable manner, it was the most beautiful smile I have seen in a long, long while.
I had my E-5 and the 50mm F2 pointed at the kid all the time, ready to spring in action. More by sheer luck than skill (though I was indeed ready), I captured that shot, and this is one shot that I am most happy about from my recent collection of street hunts. There is so much going on in that simple photograph, which begs the question, what made the boy smile the way he did?