If you could link some of the examples, that would be helpful, as there are multiple ways of doing it and some examples may use a very specific technique that I don't mention here. I generally do the classical 'move light from lamp in opposite direction of set' so that there isn't a lot of light (and if you use this method, I would recommend using daylight bulbs - yes that sounds weird, but I personally think they look better than regular bulbs when using them for night scenes). Alternatively, you could not use any of your main lights and only use small LEDs like the ones from Brickstuff (this may not work if your LEDs aren't strong enough though). In my opinion this can look really good, and if you can I would definitely recommend trying this second method. While this isn't lighting a night scene, this video by Brotherhood Workshop shows how you can utilise LEDs well.