Very timely drip email from david perell on writing Start small public
Focus on the smallest idea you can find instead — which you can explain in one sentence. Brick-by-brick, article-by-article, you will build a Coliseum of ideas.
All ideas expand when you write about them, so your thesis should feel uncomfortably small at first. Expect 75% of your ideas about a topic to come after you start writing. As you write, you'll unlock a kingdom of ideas you wouldn't have seen before putting your pen to the page.