Seeing and being seen
Most night crashes come down to visibility - either you did not see them, or they did not see you.
Use dipped headlights in poor light, keep the lights and windscreen clean, and dip for oncoming traffic. A dazzled driver is briefly a blind driver.
Drive within the distance your lights actually cover. On an unlit road that is much shorter than it feels.
Pedestrians, cyclists and animals are the hardest to see and the least protected. Slow down where you expect them, and remember they can see your lights long before you can see them.