At night, if you’re using what light there is, you need capitalize on it. One option is to look for silhouettes where you capture a subject in front of a light source.
In this image shot in New York after dark on a wet night I used the lights of the oncoming traffic to backlight this woman as she walked down the road trying to hail a cab.
Because she was moving fast I was walking behind her at a similar pace so there was no chance to stop or use a slow speed so this image had the ISO set high to capture what light I had.