I was lucky enough to find a stained shoe molding that was the exact match for one of my rooms. In another room, I painted the new cable-hiding molding the same color as the baseboard. It looks so good that it is sometimes hard for me to tell where I added the extra pieces. Decorate walls with fabric. While it's difficult to conceal a cable that goes over paint or wallpaper, you can easily bury it behind a fabric wall.
Many decorators are skilled at making slightly padded fabric walls.
This could be just the remedy to cover an unsightly cable. Run cable between the wall and the carpet or under the carpet. It is relatively easy to lift up carpet from a tack board, lay the cable and hook the carpet back to the board. If you have plush carpeting, you can bury the cable in between the edge of the carpet and the wall. Be creative with outdoor cabling.