Personalize your letter.
If you can, address it to the individual responsible for hiring. If need be, research online or make a phone call to find out who the hiring manager is.
Use email for cover letters.
Keep them short and include in the email message. Don’t send as an attachment unless the employer specifically requests one.
Spell check and proofread.
Then ask someone else to read your correspondence before you send it. It’s often easy not to notice mistakes in our own writing.
Review cover letter samples to get ideas for format and content for your letters.
Use examples as a starting point for creating your own library of job search correspondence.
Keep copies of all your cover letters, so you know what you sent to whom.