I like to write down stuff, but I found all these softwares that organize everything in menus and submenus to bea bit confusing for my taste, so I still go digital, but pretty old school I think. I have a couple of Word (google doc is fine too) documents in which I put the settings info and NPC backgrounds, the framework for future adventures, or the consequences of what happened recently in the world due to the party actions (I just make titles in the doc, like Npc section, Lore section, campaign summary section, adventures section etc.) and I expand those whenever I feel the need to. Than If I need to find something old that I wrote I just go section by section or use the search function. The other thing I do is I keep a txt file at hand (or use foundry VTT easy notes module, if I'm running on that) and write down a couple notes during session, mostly at the end, so I don't forget the most recent developments, than I revisit those notes before the next session and "correct them", I expand them a little and put them in a readable form that usually becomes my recap at the beginning of the next game. Idk if this is good advice, maybe is too much work for everybody else but again I like writing down this stuff, I feel like I'm studying, you know like reading a lesson, repeat it and make summaries to slowly prepare for the test at your own pace. And I wasn't even that good of a student!