Photo credit: Matti Sulanto
Here is what matters: show yourself, don't hide and pretend like you are invisible and sneak around like a thief or someone suspicious. As stealthy or invisible as you would like to think you are, people can see you with your camera. Present yourself as a human being, show respect and kindness, and prove that you are not a threat and you do not have ill intentions. Be open, be courteous, be polite and be generous with your smile, because how people respond to you is usually a reflection of how you show yourself to them in the first place.
People are not stupid, they know that you have a camera and you want something from them. Be up front and tell them your intentions if you have to explain yourself. Don't give excuses and don't challenge people into an argument. If your subject is not willing, move on. What is the point of aggression and in the end you end up with all the negativity dragging at your feet all day? Drop it, forget it and move on. There are plenty of opportunities waiting, just keep an upright attitude and walk on. Rejection is part of life, deal with it. Resisting is making things worse.
I like natural looking poses, like my subject is exactly right in his environment, doing whatever he is doing. I don't mind smiling human subjects in my images, after all it is a perfectly normal thing for humans to do: smile. I know many street photographers discourage this, but you are your own captain of your ship and you may set your own directions and course. You decide what you want in your image.
No matter how many times I have been on the street, no matter how many portraits I have made, each time I nailed a portrait of a stranger shot, I get that satisfaction which I cannot describe in words. That is why I keep doing it. The magic never fades.
Secret? No, not really. I just go out and shoot. I shoot a lot more than other photographers, perhaps, that itself is the secret.