If you insist on burning to optical media, I recommend using a tool like QuickPar to generate parity archives. With carefully chosen settings, this will allow you to recover data even if chunks of your disk are bad. It can take quite a lot of CPU power to create the PAR2 files, however.
When I have burnt disks for archival purposes, I have tended to go with fairly small files (~100 MB each), and enough recovery to rebuild even if three or more of the files on each DVD are bad. This has worked well for me in the past, but it is fairly time-consuming. Also, QuickPar has issues when you are dealing with sufficiently large files. I do not recall if the limit was 2 GB or 4 GB, but regardless, pretty small in this day and age.