Pick a walk that fits into an hour or two, then mark three or four places worth pausing. A market entrance, a footbridge and a row of shop windows give you different shapes and light without turning the outing into a march. Keep the route small enough to repeat if the weather shifts. One familiar block can offer more than a long list of locations, especially when you arrive before the street gets busy.
Start with the shape and position of the mark on a developed frame. A pale band along one edge, a bright orange or red streak, or a flare that grows toward the edge can point to light entering near the back door. If the mark changes position from frame to frame, consider whether it comes from a reflection or an uneven processing step instead. Write down which side of the frame is affected and whether the mark reaches the perforations.
Pair the walk with our guide to presetting focus so you rarely raise the camera to your eye.
Night scenes often look brighter to the eye than they do on a negative. Your eyes keep adjusting as you walk from a lit shopfront into a dark lane, while the film records one fixed exposure. Before setting anything, decide what should carry the picture: a face near a doorway, the warm windows of a bus, or the blue outline of a building. That choice keeps you from trying to make every corner equally bright. I usually take a moment to let my eyes settle, then frame the brightest and darkest areas deliberately.