Is your filing cabinet getting a bit jam packed? Or if you're using folders or boxes, are they getting overstuffed?
I can guarantee there are papers in there you don't need to keep anymore, lots of them.
Just like filing, where it's definitely less daunting to get it done regularly (at least weekly depending on your paper inflow), I would also recommend that each time you put something in your filing system, you see if there are a few things you can pull out.
So for example, if you've just paid your car rego and insurance like I have, you can get rid of your old rego certificate that's not current anymore. Do you also have papers for a car that you don't even own anymore? Shred them!
Do you keep clients files? Mine have evolved more into a digital system so my next task is to take the paper files that I have, scan them and gain 1/3 of my filing cabinet drawer back!
Oh and that reference material! The super important pieces of info you needed to keep for future reference that you haven't needed to use and now know you never will. Chuck them!
Yes, your filing system will change over time, the types of files you need to keep and how long you need to keep them will depend on your situation. So a regular check of what files and papers you don't need anymore will help keep your filing cabinet from bulging, making it easier to file the information you do need.