I thought I'd see Hawk Sugano's system mentioned here, but haven't so I'll share the link: http://pileofindexcards.org/
What's nice about his index card system is the simple taxonomy for organization, which can be expanded upon for specific projects or just carrying on day-to-day. Of course these can be modified, but I've found the four groups he proposes (Record, Discovery, GTD/to-do, Citation) work well for everyday capturing of ideas big and small.
What's nice about his index card system is the simple taxonomy for organization, which can be expanded upon for specific projects or just carrying on day-to-day. Of course these can be modified, but I've found the four groups he proposes (Record, Discovery, GTD/to-do, Citation) work well for everyday capturing of ideas big and small.
This, and Marc Andreesen's note to make a short to-do list nightly for the next day are my main uses for index cards. https://pmarchive.com/guide_to_personal_productivity.html