I buy a lot of my supplements off of TpT. I came up with a numbering system for the hard copies of the supplements. I assign each download a number, and as I print off a master copy, I write the number on the hard copy and write the name of the supplement on the Master List. I then file the hard copies numerically. It's so much easier to grab the printed paper and get copies rather than try to find the file on my computer. I have the Master List so I know where everything is at a glance.
Hopefully, this will help you too!