Planning and being intentional about your street photography portraits will affect the quality of your pictures. Have a clear idea of what you want to achieve. Think about what you need to do and where you need to be. Consider the time of day and how the light is. When will you most likely see a lot of people out and about?
The more purposeful you are about your street photography and what you want to achieve, the more you will build your own style.
Snapping or Anticipating
Grabbing the action as it happens requires a tight combination of skill and good luck. Anticipating potential action before it happens can often mean you get more consistently good photographs. Either approach is a matter of personal taste and style.
I prefer to find a location where I’m comfortable, not in anyone’s way and not in the hot sun. Somewhere that gives me a good angle to capture the action as it happens.
Having a good knowledge of the location helps a lot. Being aware of the flow of life in any particular place will help you anticipate when you might get the best photos.