Ask HN: How to write white papers?

I want to explore if writing white papers have resulted in increased sales from business/enterprise customers. If so, how did you reach out to them after they downloaded your white paper?

More importantly, how did you write your white paper with what tool? Are there any guides on what it should focus on? Is it even worth my time or is this an outdated method of reaching out? Are these white papers more likely to get passed around internally?