What is the best way to clean discs

The best way is to have the disc professionally cleaned and polished, but in most cases it will already be too late and you need to think of having the disc replaced.

USE BABY OIL pour it on the scratched side of the disc and use a cotton ball, cotton swabs, or GENTLY with your fingers to rub it around on the disc. start from the inside of the disc and rub it to the outside of the disc and then rinse under water and pat dry GENTLY.
For non scratched discs u can use baby oil or just rubbing alcohol but use baby oil definitely for scratches NOT TOOTHPASTE-trust me