Back in the 70s I took a course with Lou Lanzano called Street Shooting, and we were encouraged to do blind shooting or shooting from the hip. I used f 16, an appropriate shutter speed, and zone focused using the depth of field scale on my old, old Leica 35 mm lens, Tri-X Rodinaol, 1:31. Lots of good snaps and hardly ever level, but that's part of the charm. I still shoot like that occasionally.