I ODed on watching YouTube DIY videos. While I tried to save the video links and make notes of some of the ideas in the videos in order to give credit, I can't find the video where I got this idea. It's a great idea to save the wear and tear on personal devices power cords.
Mine were in pretty bad shape and this repair has given them a longer life.
Basically, you wrap the cord tightly with a strong, thin string, or strips of cloth, or ribbon starting from the top and past the damaged area. I had to tape the top and bottom to hold it in place.
DIY Tech Fix for Fraying Power Cords
Original
Repaired
Original
Repaired