Frankly, at the beginning? Anything you feel like. You can start, perhaps, with Just a title of what you're doing, pomodoros style.

Maybe a note of something you thought but couldn't follow up on that moment.

Diagrams are good. Much easier to think and much better and faster doing by hand. I always get distracted by the tool when I'm drawing in a computer. Even artist-modd

I also make bullet points of general ideas that I'm trying to accomplish.

Doodles.

Important thing is, don't fret. Over time you'll find how it works for you.

Every time you look up something on StackOverflow, refer to the API docs, or refer back to the ticket, use case, or requirements document, make a note of your question and the answer. Even when you stop typing to take a break for a moment, or after pushing code while you wait for the ci/cd pipeline, note down where you are and your last action or change.

Every time you start to write a TODO comment, make a note instead, or also.

Consider Kent’s Beck’s recommendation to write down every decision you make.

For me, if it's worth thinking about it, it's worth writing it down. Doesn't matter if it's a todo list I just came up with, a system diagram, whatever I am currently working on, or thoughts on a human interaction I just witnessed. The act of writing it down guides me in my thinking.

I really only find it useful when I'm investigating or troubleshooting some system I'm not familiar with.

A stupid yet accurate analogy is I turn up the log level for my brain lol

It's basically just a log file of everything I did and the result so I can pick it back up later, plus I include timestamps which helps me realize when I'm spinning my wheels for too long.

For building stuff, scribbling diagrams and flows is more useful if I need to work out something complex.

I write down:

- To-do items (with empty checkboxes)

- Notes about what I did, every so often. Or what I talked to someone about, what was decided.

- If I'm programming, I try to have a kind of plan for the next fifteen minutes / hour in a few sentences. "Going to refactor this now." "Updating the state here so it can hold this information." "Adding a component for this". Just so that I do think about what I'm going to do for a bit.

That sort of thing.

Apart from the to-do's the main point is to keep my focus, when I'm writing thoughts on paper I'm not on Hacker News. It doesn't matter all that much what the writing is, to me.

I always try to write what I did. Somehow the act of writing has a magical effect on my retention.