Always tell someone where you are going, the rough route you are going to take as well as when you leave and intend to get back. That way if something does happen to you during your run (say you fall and hurt your ankle and can’t walk home) someone will be able to come and find you. It’s not always practical to take a mobile phone with you but if you can, you should.
If you are running in an urban area then try to keep to the paths at all times. If it’s anything but bright daylight, you should wear something high-visibility. This could be a cheap hi-vis vest over your running clothes, or piece of running attire made for night/winter running as they have reflectors on them.