Face facts: Some people will never read your cover letter. The rest of the people may trash your resume if it does not include a cover letter. Others will value the cover letter over all other application materials. Since you can't know for sure which type of employer or recruiter will receive and review your materials, assume the cover letter is a crucial piece of your application package.
Don't make these 13 cover letter mistakes and you will be ahead of the game:
1. Forgetting to include a cover letter.
For reasons noted, the cover letter is important, especially if the job description requests it. When you leave it off, you may look lazy (at best) or appear to be someone who cannot follow instructions (at worst).
2. Addressing your cover letter generically.
"Dear Sir" is totally out of the question, since it is sexist and "To whom it may concern" makes it clear that you didn't think it was important enough to try to identify the person in charge of the search. It may be difficult to identify the correct person to address your letter, but you should try. Make a valiant effort to identify a name to include. Contact the company to ask for the correct name and use your Internet research skills to see if you can confirm a specific person to send your letter. As a very last resort, "Dear Hiring Manager" may not keep you totally out of the running, especially if the company has gone to great lengths to shield the exact name from the applicant pool.
3. Adding your cover letter as an attachment and writing a brief note in the body of the email.
If you apply via email, include your cover letter's contents as the body of the email you send. That way, it is very easy for the hiring manager to decide whether to open your attached resume or press delete.
4. Sending a boring or terse cover letter.
If you're going to include a letter, it might as well be good enough to give you a better chance to land the job. If you send a formulaic sounding letter with nothing more interesting than the fact that you are applying for job No. 123 and that you saw the ad in XYZ.com, you won't pass the cover letter test for those sticklers who demand a cover letter. Make sure you write a letter that is interesting enough to read.
5. Missing an opportunity to make a great connection or to tell an interesting story.
Not everyone has a great story or reason for applying for a position, but if you do, use the cover letter to tell it. Was it the company where you launched your career, and you are ready to come back? Say so. Did you always admire the organization's television ads growing up, and now you are applying to help create new ones? That's a great story, and the cover letter is the place to share it.
6. Being self-centered.
The cover letter should not be a note detailing what you want. If you appear self-centered, that delete key is always handy.
7. Including errors or typos in your letter.
This is the kiss of death for many job application materials. Even if the job does not require you to wax eloquent regularly or to or create written materials for the company, if you misspell words or send a letter with typos and grammatical errors, it's a mark against you in a competitive field. Edit your own note carefully and ask a trusted friend to review it. Read it out loud to be sure you haven't left off words or made a typo that spell-check doesn't pick up -- for example, if you've said, "I'd be a terrific manger" instead of "manager."
8. Not targeting your letter.
Just as you should target your resume for every job so you're most likely to pass the company's computerized resume screening system, you should also target your cover letter to each position and organization. Include specifics about the company and describe why you are a good fit for their job. Use the job description and information you can find out about the job and organization online to choose the best details to include. If you send the same cover letter to every company, you are missing an opportunity to stand out from the crowd.
9. Writing a novel.
No one needs a three-page cover letter, no matter how interesting or perfect the candidate may be for the job. Just as you don't want to be too terse, don't think you need to tell your life story. Write the equivalent of about one typed page at most.
10. Using the cover letter to repeat everything in the resume.
While you should make sure to include everything important in your resume (in case this hiring manager does not read cover letters), don't just summarize your resume in your cover letter. Take the opportunity to make direct connections between the job description and your skills. Consider creating three headlines based on information in the job description the employer wants and listing under each topic why you are a good fit. The more you can make a direct correlation between their needs and what you offer, the better your letter will be.
11. Exaggerating.
Don't say, "I'm perfect for the job" if you know you are not. Be honest in your cover letter and identify the best matches between your skills and their needs.
12. Being too humble.
The opposite of the braggart, who is "ideal" for every job, the overly humble job seeker may actually apologize for applying and explain the skills he or she does not have for the job. Hopefully, it's obvious why the "why I'm not qualified" strategy is less than optimal! You may be applying for jobs that are a reach, and when you do, focus on what makes you a good fit and don't dwell on the negatives.
13. Going overboard with the sell.
Unless you are actually applying for a sales job, think twice before including language such as, "I'll call you on Friday to schedule an interview." This may be a turnoff for some hiring managers. Is it appropriate to indicate that you hope they agree you're a good match and that you will follow up as of a certain date, but you could lose the interviewer's attention if you act as if you are in charge of the process.
Source: AOL