Ask HN: How do you organise your book notes?

Assuming we are talking about technical writing and nonfiction, my preferred method is outlining. I will typically have one section per chapter. My next level of bullet points will be the major conclusions that the work draws from that chapter. The level below that will be the supporting evidence for each of those conclusions. In the case of math/cs work, that is where I will put the proofs.

Additionally, I will use several notations to indicate items of special interest. I will write "TODO" to indicate future tasks I want to do inspired by that section of the book. Examples of this typically include researching other papers, looking up the definition of a term I do not understand, etc. I will then change this to DONE once complete and update the relevant section of the notes.

I also will tag items as "IDEA" for potential areas of future research, product ideas, etc. The advantage of using these tags is that I can keyword search them in the future easily.

For statements I deem particularly important, I will informally cite them with PN (for example, if something was on page 55, it would read PN55) to indicate exactly where in the work I found that fact.

I tend to take my notes directly in Evernote and I tend to write them while I am reading, versus writing a large summary at the end.

The big downside of Evernote is that Evernote does not support LaTex. I have read some hacks online where people claimed to get this working via various methods, but I could never make it work for me. In the cases where I need to write detailed equations, I will use a simple online latex editor and paste the resulting image into the appropriate section of Evernote. This historically has been the part of my system that causes the most frustration.

In graduate school, I was an adamant paper note taker. Now I have a dozen large binders containing years of work that I am reluctant to get rid of ("in case I need it some day"), but that manage to annoy my partner by taking up valuable closet space.

Instead what I try to capture with book notes are memorable or densely insightful passages. I use Notion to store these notes, since Notion's database feature (similar to Airtable but more powerful) makes it easy to connect useful passages to other metadata for quick reference later on. For example, I have a database called "Quotes" where I create a new record for each insightful passage I come across. Each quote record is connected to records from the following other databases: Books, Authors, Topics.

It's not very lightweight, but the payoff is immense. I routinely think, "Damn, what was that Paul Virilio quote about second-order effects again?" And I'll quickly open my Authors database on or my Topics database on and find my quote: "When you invent the ship, you also invent the shipwreck."