I'm very new at the street photographer thing too, but have been trying. I like Oh Two's advice. It's good to be open about what you are doing. In my limited experience, it always seems better to say 'hi' and ask if they mind. The picture will be better, and it's a way to connect with people who you might otherwise not meet - isn't that what a lot of us are trying to do? be curious, ask questions, shake their hand, tell them what you are doing, whatever.
The other advice on shutter speed f/ is great too. Its no good to fuss with a meter and your camera once you pick a subject. Its about practice and being prepared.
I've a couple things that I would like to add.
- The wider the lens you use the slower the shutter speed can be.
- I have a Mamiya 7. I've attached a couple small tabs of tape to the lens barrel, so I can focus the camera at my waist by feel with my thumb.
- I have a few cameras that I use. I've noticed that the Mamiya and the old Canon RF are conversation starters (no funny T-shirt needed!). Someone always comes up to me and says "nice camera" , when they do I take their photo.
Thanks, for the good input on this thread.