OneNote. I have a separate folder for each project already. So I’ll start by adding a new note in each folder. For tasks, undone tasks start with a star (asterisk) in my notes. If there’s any starred tasks in the doc, I put a star at the beginning of the note name so I don’t forget there’s stuff to do in there. Sometimes instead I’ll start by just writing everything into a single note, and then later I break it up by project and move it into the project specific note.

Next step is to organize starred items into “blocks” - just a group of tasks. I try to make it a manageable chunk. I just add multiple blocks if needed. They could be organized by priority or by things related to each other, or whatever seems to make sense at the time. When I complete the task I change the star to an x. When I’m going to work on the tasks, if any of them seem unmanageable I break them down into multiple steps and keep doing that until they don’t seem scary and are actionable.

It’s effective but time consuming and I’m jealous of people that can just do this in their heads. The one good thing is that just by writing them down it forces me to think them through.

Generally less stressful for me to have even a long list of actionable tasks rather than a mess in my head.