Stop waiting for decisive moments instead look for the human interaction. Your photograph will inform your perspective as where you hold your camera, straight, up, down on the ground or crooked.
Photograph what you see and what moves you emotionally. It is a story said within a single frame. Capture contrasts which can be anything like BIG/small, Old/young. Shoot characters on the street and try reflections to get from a different approach.
FIND THE STORY
Photography is exposing the ordinary and usual as incredible. There is always the story behind the photograph. Having a Signature on your photos are important as it carries the label of your point of view.
Most photographers do a black and white as colours can be distracting especially a street scene. But don't shun away from doing colours, it will give a colourful and entirely new perspective to the frame. Avoid using HDR (high dynamic range); it sometimes ruins the entire colour tone.
Watch while photographing persons who don't want to be photographed (pun intended). Shoot quick, take a couple of frames and put down the camera back down. Shoot whatever makes you happy.
Here, you don't have a client whom you'd have to satisfy, you are the client so make sure you enjoy your own work. Wear comfortable clothes and preset camera settings and effects to avoid missing the moments.
Pick a focal length of 50mm – 30mm to have nicer shots. You can't take pictures of whoever is in that public space and sometimes there isn't something happening in front of you for you to take that shot immediately. You'll have to look at the subject and consider the possibility. You'll capture that moment or you might go away with nothing, well that's how it is.
THE THREE COMMANDMENTS
If you're shooting on the streets it is street photography. There can be lots of rules around street photography.
1. It is okay to focus on details
2. Go more classic like people, emotions, intersecting lines, etc,.
3. No beeps and lights for street photography as it might startle the subjects
But if you're just starting out, look for interesting scenes and timing. Look for the scene, wait for the people or just a position, or instead of focussing on scene, focus on the people. So if you think the person looks lovely, track him.
Street photography can also be street portraits where you can approach the subject to pose or just grab it on the spot (unopposed moment). Use the shadows to your advantage. Working in shadows could give you some really dynamic shots.