I don’t. I am not a fillier. My filing system is much closer to the W.C.Fields’ method as shown on his desk in the movie [The Man on the Flying Trapeze].
I tell everyone I’m not messy and unorganized, my mind is just too complex to be limited by an organized filing system. [but no one buys that idea] It’s one of my great frustrations that I can not get my wife to understand why I get upset when she “cleans up my mess”, that when she “organizes my stuff” it destroying the physical record of my flow of interest, it’s like mucking about inside my mind. I’ll never be a disciple of De-cluttering Queen Marie Kondo,
http://digitechlaser.com/printer-cartridges/2017/03/22/meaning-behind-messy-desk-method-not-mayhem/
However, I think one can gain great insight by keeping such records.
It reminds of of Edwards Demming’s statistical method for continuous improvement quality control. Wherein the idea is not to make a product with zero defects, as much as it is to determine the best product to make, and to make it well. Make the best wrong product, and you’ll still soon be out of business.
I recall reading a blog post by the Tenkara Guides guys about their trip to Japan and fishing with Fuji Hiromichi. While everyone else was expending time trying to decide what kebari to use that day. Fuji-sensei quickly picked the correct kebari that would be the most attractive to the fish feeding that day. Maybe Hiromichi-san is also a good record keeper. Or maybe it’s just decades of fishing, while paying attention.
I purchased a kindle book a few years ago. “Year of the Spider”, by Philip Storey. He keeps a detailed record of his flies. Each fly was described, with a note about the season or conditions when that fly has proven effective.
Followed by a record of : day of the week, date, time, temperature, percent humidity, wind (calm N.E), barometric pressure (rising or falling). A note about the weather the previous couple of days, and how it effected the stream conditions. How the day’s fishing went, other varying observations. Then a conclusion.
Tenkara Ajari, [aka Kazumi Saigo-san] is also a dedicated record keeper. Described by Paul Gaskell as being a human database. That other anglers in Japan will call and ask what stream to fish to target a specific species of fish that weekend.
https://www.discovertenkara.com/blog/ajari/
On Dr. Ishigaki’s blog,
http://www.tenkaradaio.sakura.ne.jp/
on the right side of the page you can find a link [西郷さん 尺ものを釣るマル秘テクニック, Saigo-san’s big fish secret fishing techniques or some similar translation]. The link is a file - saigo.pptx. It’s all in Japanese language of course. So difficult to read, but it is filled with information about streams, kebari, tackle, flow charts, etc.
Anyway, point is. People who keep such records can gain a lot of fishing insights, or just pleasure from keeping them. Maybe even earn a good reputation from what they’ve learned.
But I am too scatter-brained to take up doing that sort of thing. My method works for me. Well, it does, until my wife, organizes it for me.
Oh, I prefer paper journals too. Yours is nicely done.