How to Build your Digital Library of Ideas

Ideas are the currency of writing. Writing is not about generating text, it is about creating ideas, and you create ideas by building on top of other ideas - you combine ideas, expand on ideas, remix ideas, make surprising connections between ideas, apply ideas across different fields.

So the most powerful tool you can have as a writer is your own digital library of ideas (a so-called "second brain") which you build and improve over time.

To build your library of ideas, you need to create an Idea Capture System - a method of collecting all the most interesting ideas you have in one place, and organizing them in a way that enables you to easily search through the ideas you have collected over the years, and turn them into creative output.

Here's how to do that.

Choose the right tool

Most people use Notion or Obsidian.

I highly recommend Obsidian, because it stores your notes in plain text rather than a database or a proprietary format. The tools will change over the years, but the plain text will never get obsolete. Obsidian is available on all platforms, seamlessly syncs your notes between them, and has all the features you need to create, organize, and search through your ideas.

Build a habit of capturing ideas

Capture:

Useful ideas that naturally occur to you as you work on your projects and live your life.
Interesting ideas you learn from things you read, watch, and listen to.
Ideas you gather when you research your posts.

Save all the original ideas you have, and only a small fraction of the ideas you consume (the top 5%).

There are automated ways to capture certain types of ideas (like highlights from books), but I recommend writing them down manually - it forces you to understand and process the ideas, distill the best ones, summarize them, and express them in your own words.

Organize your ideas

You want the process of capturing ideas to be as easy and seamless as possible (so that you do it more often). That's why you create a document where you capture "fleeting notes" - rough, unedited, disorganized notes you can easily take while doing something else, without being distracted by the effort of writing.

Every week, go through your fleeting notes, and organize them into "evergreen notes" - cleaned up, edited, and summarized versions of the best ideas you've captured.

For every idea, create a new file where you summarize it as concisely as you can.
Use descriptive titles that capture the entirety of the idea as clearly as possible.
Organize the ideas using folders or tags, to make it easy to retrieve them later.
Create links between the related ideas, to make it easy to find surprising connections between them.
Create "Maps of Content" - files that contain links to all the relevant notes on the same subject (like a table of contents in a book).

Use your library to generate creative output

Don't forget that the ultimate purpose of your idea library is not to just store knowledge, but to help you create things.

Take particularly interesting ideas and turn them into tweets, threads, atomic essays, blog posts, or videos.
Take multiple ideas related to the same subject and assemble them into longer articles, books, or courses.

With this powerful method, when you start a new writing project it is already 60% finished - you already have most of the ideas, you just need to fill in some gaps, organize them a bit more, and convey them in a way that's easy and fun to read.