Best approach to make seo audit report?

Write it for the person who reads one page. Summary first: the five or so issues that matter most, ranked by impact, each with one line on what to do. Most clients never get past that page. Then the detail, in sections: indexing and crawl (Search Console's Pages report, broken links, redirects, sitemap), speed and Core Web Vitals, on-page (titles, headings, duplicates, thin pages), content gaps, and links. A crawler does most of the grunt work. Screaming Frog's free version covers up to 500 URLs. For every issue: what it is, which URLs (attach the list rather than pasting 300 rows), why it matters, the fix, and a priority. A report that says "47 pages missing meta descriptions" with no priority gets ignored.