A simple way to determine direction at night is by the moon. Draw an imaginary line that connects the tips of a crescent moon. Where the imaginary line touches the horizon is approximately south. The higher the moon in the sky, the more accurate direction will be.
This only works when there is a crescent moon, about 14 days out of 28, and of course when there is no cloud cover.
You can use this technique if you’re in the southern hemisphere, but where the imaginary line touches the horizon is north.