When we take notes, it should not become a stack of forgotten thoughts. Our notes should be a rich and interconnected collection of ideas we can draw on regardless of where our interests lead us.
A smart note is a reliable and simple external structure to think in - like a second memory. It compensates for the limitations of our brains while turning our thoughts and discoveries into convincing written pieces.

German sociologist Niklas Luhmann (1927-1998) designed his slip-box made up of index cards. They were thematically unlimited. His simple system produced a prolific output. Over his 30-year career,  Luhmann published 58 books and hundreds of articles while completing his two-volume masterwork, The Society of Society (1997).  He regularly pointed to his slip-box as the source for his fantastic productivity.

• He wrote down any interesting or potentially useful ideas on uniformly sized index cards on one side only.
• Each new index card got a sequential number, starting at 1.
• When a new source was added to that topic or something to supplement it, he would add new index cards with letters added to the number (1a, 1b, 1c, etc.)
• These branching connections were marked in red as close as possible, where the branch began.
• Any of these branches could also have their own branches. (For example 21/3d26g53)
• As he read, he would create new cards, update or add comments to existing ones, create new branches from existing cards, or create new links between cards.

• This system could extend indefinitely. Each card had a permanent ID number and could, therefore, be referenced from any other card.
• The branches created "strands" of thought that one could enter at any point; downstream to elaborate and upstream to its source.
• Topics that had been extensively explored had long reference numbers, making their length informative in itself.

Writing is the medium in which thinking takes place.
Writing does not begin when we start to put words on a page. It starts much earlier, as we take notes on articles and books, podcasts, conversations, and life experiences we have. 

These notes build up as a byproduct of reading and is a way to organize our thoughts and to keep track of the information we consume.

We are typically taught to begin writing by picking a topic as the first step. But we can't decide if we haven't read about anything. And the decision to read comes from an existing interest.

Creativity never starts from a blank slate. We start researching long before, with rich material to work with. That is why an external note system is so critical: It makes the writing process possible.

Writing is often taught as a collection of tricks: brainstorm ideas, make an outline, use a three-paragraph structure, repeat the main points. Each one makes sense in isolation but requires a holistic perspective.

Writing needs a workflow - a repeatable process for collecting, organizing, and sharing of ideas. A good system is stripped from clutter. A reliable collection of notes is all we need.

Many people take notes in an ad-hoc fashion. They might underline a sentence or write a comment in the margin. If they have a good idea, they write it down in one of many notebooks. They might save an except from an article. In the end, their different kinds of notes in many places and formats creates a massive project to organize and become mostly unusable or forgotten.

A standardization of notes enables a mass of useful notes to build up in one place.

We will become better when we intentionally expose our work to high-quality feedback. Feedback comes in the form of peers, teachers, social media, rereading our own writing. However, notes are available any time you need it.

When we write notes in our own words, we practice the skill of insight. It enables us to separate the parts that truly matter from those that don't.

Books seldom contain only the precise insights you were looking for. There may be many ideas, but only a fraction will be useful and relevant at a given time.

Note-taking enables you to collect all the ideas, and re-use them at a later stage without re-reading all the books again. It also increases the chances that you will stumble upon some forgotten ideas in the future.

Organizing notes by topics and subtopics is a classic mistake. It prevents you from discovering meaningful connections between them. While organizing by topics is useful for a librarian, it is not for a writer.

Instead, organize by the context in which it will be used. Ask: “In which context will I want to stumble upon this again?”

We are often told to "make a plan" upfront and in detail. Success is then measured by our ability to stick to this plan.

In creative work, questions change and new directions emerge to foster a rich ground for accidental discoveries. We should focus on steering our work towards our interests and what we consider relevant. It will energize us to continue in our work without relying on much willpower to do it.

A slip-box system will lead us to save contradictory or paradoxical ideas. These ideas become very valuable. It will be easier to develop an argument or pros and cons than with a string of one-sided arguments or quotes.

It will also go a long way to counteract confirmation bias - our tendency to take into account only the information we agree with.

Any ideas that are kept private are as good as the ones you never had. Everything we write down and share with someone else counts: notes to a friend, homework to a professor, emails to a colleague, presentations to clients. The feedback you receive will propel your thinking forward.

If you write as if it is the only thing that matters, you will be more deliberate in your reading and be more focused, more curious, more rigorous, and more demanding of your own writing.