1. When it's worth writing one
Plenty of applications skip the cover letter, and that's fine when none is asked for. But when a posting requests one, a generic letter hurts you more than no letter would. It signals you sent the same thing to fifty companies.
Think of it as the one place you get to sound like a person instead of a list of bullet points. Use it to connect your experience to this specific role.
2. Open with something only you'd write
Skip 'I am writing to express my interest.' The reader has seen it a thousand times and it tells them nothing. Start with why this company or this role, in a line that couldn't have been pasted into any other application.
Weak
I am writing to express my interest in the marketing position at your company.
Better
Your ad mentioned you're rebuilding the email program from scratch. That's the part of marketing I like most, and I've done it twice.
3. Don't just retell your CV
The letter isn't your CV in paragraph form. Pick one or two moments that show you can do the job, and tell them as short stories with a result at the end.
Tip
Borrow a few words from the job ad so it's clearly written for this role, then say something the CV has no room for.
4. Keep it short, and send the right one
Three or four short paragraphs on a single page is plenty. If you can find the name of the person hiring, use it. Close by saying you'd welcome the chance to talk, and leave it there.
Watch out
Never send the same letter to every job. A recruiter spots a template instantly, and the wrong company name in the first line is an automatic no.
Frequently asked questions
How long should a cover letter be?
One page, three or four short paragraphs. Anyone reading it is busy, and a tight letter respects that.
Do I still need a cover letter?
Only when the application asks for one or you have something specific to say. A weak, generic letter is worse than none.