I use a LARGE Magic Fiber cloth similar to what you would use to clean glasses, monitor and tv screens.. Works great. Don't put anything on it.. Wash no soap or detergent.. More or less getting rid of accumulation of dust and tiny particles you can't see. You can use same for the laser.. Very, very gently. Those disks that have brushes etc Kill lasers.. but up to you. Just letting you know what works for me.
Self burn cd or dvd's that you burn yourself something don't last very long specially if you used cheap disks.
I suggest before you do ANYTHING take the troublesome dvd's or cd's to your buddies place and see if they work on his/her.. If they do then its your machine. If they don't it the disks that are the problem
Just so you know I been messin with that stuff for years.