File management

My work establishment has recently issued instructions on "Good File Management".
It makes a number of points (such as, do your filing regularly!) but  I was particularly interested in the following:
-  The electronic file is the primary file and should be comprehensive.
-  Don't print every email (but store them in the electronic file).
-  The physical file contains documents which originate in paper form, but these should be scanned so as to be placed on the electronic file.

 All good points - particularly the acceptance that the electronic file ought to be comprehensive (even though it is a bit of a challenge if you were brought up in an era of paper!) - but for many of us, there's still some way to go in organising the electronic file.  We live in an age where there are more documents, albeit  electronic, associated with each transaction, and filing them all represents a challenge, at least for me.    Obviously the electronic file needs be be split into folders, but deciding on the folders isn't always easy.  Assuming that one of the reasons that a file is maintained is so that, if necessary in the future, the course of the transaction can be discerned, the filing of emails  by author (which I've certainly encountered) isn't necessarily the best way of making it easy for a person in the future to recreate the "big picture".