The hardest lesson you will ever attempt to learn is.....
Try to unlearn all that has cluttered your mind. Forget all the techniques, styles etc you have learned.
Forget what everyone, especially me has tried to drum in your brain.
It is taught by many to try to see something as if your seeing it for the first time.
I teach to try to see something as if it's the last time.
Breathe only for your next image.
Connect your eye, heart and mind and let the finger do the rest.
Everytime you do this without question, you've made a image that is the Decisive Moment.
Elsie, Don's been giving me (and many others) roughly this same advice since I've known him. I know its meaningful because he's done some of the best street photography I've seen, but I have to admit I don't know quite what he's talking about. My loss.
My limited advice, for whatever little its worth, is that getting close is really important, as others have said. Try whatever different techniques seem to make sense but you have to get comfortable enough with the technical parts of the shooting process that you don't have to think about them when you're doing it - you just do it. This takes time - I've tried a number of things in the past couple of years I've been doing this street photography thing. Now it feels very natural, but I'm not sure exactly when it became second nature - it was a gradual process. But its really tough to nail the moment when you're thinking about your camera.
Once you get comfortable with HOW you can shoot and get close, the main thing, as Don has also said innumerable times, is to live for the MOMENT - watch it develop, anticipate it, get in position for it to the extent you can. Its a real dance, its improvisational. Most of us miss waaay more than we really hit. But if you keep dancing, you'll hit plenty.
The main thing is to have fun. Even in my earliest days street shooting, when I didn't have the smallest CLUE about what I was doing, there was something about the process that I just loved. That's what kept me coming back and allowed me to get better. If you're having fun, just stay with it and it'll come to you. I've only been doing it a couple of years - I'm competent but hope I continue to improve and expect if I keep shooting and loving it, I probably will. Don's been doing this for many many years (I'm not sure exactly how many, but I've seen some of his old film work and its really startlingly good). Bottom line is it takes time and committment. The rest should take care of itself. And none of our advice will matter near as much as what you discover for yourself about what works for you...
-Ray