Get on the top deck of a bus and just watch the world go by down below – and if you see anything interesting get off the bus as soon as you can.
Find an interesting background because it can sometimes be half of a photograph – and then hope that one or more elements might move into the scene to make it more complete.
Or reversing this strategy follow somebody interesting who might perhaps be carrying something unusual and catch them against a background to make an interesting juxtaposition.
Shoot vertical more often because on the street you often have more control over the top and bottom of a scene.
Don’t crop! None of the best street photographers crop their images. Try to crop in the frame as you take the photograph.
Believe that you are half invisible on the street. Of course you are not but it is an important mindset.
Don’t use a long lens. There’s a quote I heard recently that summed it up, something like: The best lens to use is your feet. It is so true, don’t be lazy, get closer… use your feet.