The link below from Seek uses a nice infographic to show the distinction between a good cover letter and a bad cover letter.

https://www.seek.com.au/career-advice/article/cover-letters-the-good-and-the-bad

One of the great things about cover letters is you sell yourself straight up.

One of my clients told me that my cover letters were like a Muhammad Ali punch. That’s a complement.

Every paragraph contains a well thought out reason why they should employ you.

Each paragraph should include your relevant or transferable experience and achievements, academic qualifications and maybe even volunteer work.

I always include a professional motivation for applying.

What is it about that particular job that draws you in like a magnet.

If there’s personal motivation, include a line or two about that too.

Remember, your cover letter doesn’t simply repeat what’s already in the resume.

Write why you are a strong candidate for that particular job.

Think of your cover letter as a laser beam. It has to focus sharply on aspects of the advertised role.

I try to find out the surname of the hiring manager as an added personal touch but that’s not always possible.

Check the cover letter for spelling and grammar mistakes