This is a very good idea and yet I go pale at the thought of trying to do it:

While online portfolios are incredibly important for showing off your expertise, there’s a second kind of portfolio—a completely different kind of portfolio—that can be a really valuable tool for all freelancers: an Ultimate Archive.

An Ultimate Archive is an “offline” portfolio for organizing and analyzing your body of work. It’s a simple spreadsheet with a link to everything you’ve ever written on the Internet. You’re likely the only one who will ever see it. But besides tracking your bylines, there are many different ways it can help you land new clients and improve how you approach your career.

Why You Need an Ultimate Archive of Your Work – Aubre Andrus, Contently (17 December 2014)

Read the full piece for more on why and some on how to do this for yourself.