1. Slow down. To be good at street photography you need to be curious. Walk down the alley. Stop and look behind you to see the environment from a different perspective. To find those little things that bring a composition together you must slow down. There is an exception for every rule, some people can quickly walk through life and find all the great shots. But for most of us, just slow down and really observe.
2. Pick your side. If one side of the street is in sunlight and the other is in shadow you will find different photos on each side. The side with the sun will tend to produce more graphic photos because of the shadows that are produced by the sunlight. The other side will produce flat light that will give a different look. Both can produce great photos. Most photographers gravitate to a certain kind of light. They just prefer the look. That is how you develope a style. Look at your photos, I bet you prefer a certain kind of light.
3. No focus. Autofocus is great. But no focus is even faster. Learn how to utilize the hyperfocal distance to increase the amount of keepers you get. The old photojournalist mantra of "f8 and be there". This means don't worry about the settings and just get the shot. Because that is all that matters.
4. Go it alone. It might seem like a good idea to have someone along while your shooting to keep you company, but try to go it alone. The less distractions the better. Multitasking is just doing two things poorly. To make great pictures one must be in tune with ones surroundings. It's the little things that make a photo and splitting your attention with someone else is doing yourself no favor.
5. No dandruff. Yes great photos have been taken of the back of people's heads. The best way to make a boring photo is to shoot the back of someone's head and call it street photography. Look at Henri Cartier-Bressons photos, almost all faces. I'm not demanding that you stick a camera in someone's face, but a more compelling photo is usually obtained when we see a persons eyes. The line in portraiture is the eyes are a window to a persons sole. Same in fashion. Don't sneak around, people already see you and most don't really mind if you snap one or two photos. Faces make photos more interesting.