If your project is worth doing, then it is worth backing up! This means you should use version control for every single project you are involved in. You will quickly be surprised at how many times you wish to go back and rescue some deleted code, or to restore an accidentally deleted file.
It becomes even more important when collaborating and many individuals may be editing the same file. As with the previous chapter, this is an area which data scientists have discovered much later than computer scientists. Get it up and running in your own workflow and you will reap the rewards in the future.