There's not much you can do with your cd/dvd if it gets scratched but there is a method which I discovered which really works
All you need is:-
Lip balm or Chapstick or Vaseline (any one of these will work)
Lintr free cloth (eyeglass cloth will work)
And most important brain (in a good working condition)
Step 1: Apply Lip Balm
Just apply the lip balm on the cd/dvd in a circular motion starting from the center towards the edge.