Not only should you have a flashing rear light, but a flashing front light as well. You want oncoming cars to see you when riding on a narrow road or through an intersection.
Be sure to turn your rear light slightly towards the road. It will make it easier for cars to see you as well as prevent the light from flashing in the face of the rider behind you.
For added safety you can invest in a helmet with lights or a back light with built-in radar. Knowing a car is approaching and how far back will help you make the right decision.
Finally, try to avoid heading into the sun when it is rising or setting. If the cars are blinded by the sun, they can’t see even the best light. Get off that road and take a different route.
Quote of the week: If someone finds me collapsed on the road, please pause my Garmin.
Here is an article that further explains this subject and reviews the best lights for 2020: