How to write a cover letter

Three paragraphs is enough

One: why this job at this employer. Two: the single most relevant thing you have done, in detail. Three: what you want to happen next.

A cover letter that restates the CV wastes the one chance you have to say something the CV cannot.

Name the employer and mean it

A letter that could be sent to any company reads as one that was. One specific, accurate sentence about why this role is worth more than three paragraphs of enthusiasm.

Address it to a person if you can find one

If you cannot, "Dear Hiring Manager" is fine. "To Whom It May Concern" is not — it reads as a form letter because it usually is one.