Recently I have noticed that my hard drive was getting filled and it is high time I did some cleanup. However, it is quite tedious work to check each and every file to determine whether I need it or not. Luckily, I always maintain my important files according to a predefined structure of important folders. This means, any file that isn't contained in an important folder is not an important file and can be deleted. Note that, there might be unimportant folders inside an important folder.
This is a companion discussion topic for the original entry at https://toph.co/p/file-cleanup