Copied verbatim because I love this:

1. Observe the world, pay attention to things.
2. Jot down snippets of observations/ideas in a single Google Docs document (available on almost any platform). Don’t try to organize it. Keep it really simple. The key is to keep it low effort and frictionless.
3. Look over the Google Docs document from time to time. When you have enough ideas coalescing in a cluster/theme, feel them out. When the cluster feels like it’s ready i.e. you feel an emotional connection to it, start writing. Important tip: don’t feel you have to finish writing in one sitting – you can stop, let your writing sit, and keep re-clustering until you have something that is worth putting out there.