How do you write title tags for seo?

main keyword near the front, say plainly what the page is, and keep it around 50-60 characters so it doesn't get cut off. brand at the end if there's room. every page needs its own, duplicate titles are one of the most common things audits flag. also google rewrites titles fairly often when they don't match the page well. if yours keeps getting replaced in the results, that's the hint.