Backing up files. It never hurts to take security copies of important files, such as photos and financial data. One cheap and easy way to do this is to âburnâ folders full of these files to blank CD-R or DVD discs. Backups need to be reliable so donât buy the cheapest discs, and donât use rewritable ones (eg CD-RW). Also, always use the âwrite at onceâ option and burn a whole disc, even if itâs not full. When you are saving data, it is not the time to save pennies.