Mistake #6: Being Vague
If you're replying to an advertised opening, reference the specific job title in your cover letter. The person reading your letter may be reviewing hundreds of letters for dozens of different jobs. Make sure all the content in your letter supports how you will meet the employer's specific needs.
Mistake #7: Forgetting to Customize
If you're applying to a number of similar positions, chances are you're tweaking one letter and using it for multiple openings. That's fine, as long as you customize each letter. Don't forget to update the company, job and contact information -- if Mr. Jones is addressed as Mrs. Smith, he won't be impressed.
Mistake #8: Ending on a Passive Note
When possible, put your future in your own hands with a promise to follow up. Instead of asking readers to call you, try a statement like this: I will follow up with you in a few days to answer any preliminary questions you may have. In the meantime, you may reach me at (555) 555-5555.
Mistake #9: Being Rude
Your cover letter should thank the reader for his time and consideration.
Mistake #10: Forgetting to Sign the Letter
It is proper business etiquette (and shows attention to detail) to sign your letter. However, if you are sending your cover letter and resume via email or the Web, a signature isn't necessary.