A good cover letter will get you noticed, and may get you an interview. You should include solid details about yourself and your previous experience, write professionally, but with some personality (preferably your own), and allow the hiring manager to see exactly why s/he should hire you. A good cover letter will create interest in your resumé, which will fill in any blanks. Make the letter sparkle!
== Start in your head ==
Don't know what to write? Get clues from the list of duties in the job announcement. You've already read it once and decided that you can do the job, so get specific and start jotting down notes. It doesn't have to be a polished document right out of the gate.
You should ask yourself some questions about your employment experience that will help you remember previous successes. Did you:
• Lead any special projects or serve on special teams?
• Improve an end product?
• Increase management/employee or company/client communication?
• Save the company money, time, or space?
• Earn any rewards?
Include everything that you're proud of, even the small stuff, because you never know what will impress a hiring manager.
== Generic is junk, details are dazzling ==
While your resumé holds more generic data, you should tailor your letter to the specialized knowledge, skills, and abilities that relate to the job. Expound on your resumé information, focusing on the items that will help you be the best (web designer, paralegal, receptionist, sound technician, IT consultant, butcher, baker, candlestick maker, etc.) that you can be. It's all in the details.
For instance, if your letter is geared towards a financial position, tell that you were expedient and careful when using Excel or Quicken, prudent when handling company expenses, and confident when you successfully saved $35,000 on a specific project's account. Quantify whenever possible.
Perhaps you're after a technical writing job. Tell how familiar you are with Adobe or Quark, how quickly you catch spelling, grammar, and syntax errors, and how experienced you are in explaining specialized jargon and terms (medical, legal, political, technological, etc.) to the general public or more specific audiences.
Maybe you're answering an announcement for a web designer and editor. Tell how long you've been working with HTML and CSS, how familiar you are with web-specific fonts, the latest browsers, search engine optimization, and how you increased the number of web visits by 72% after redesigning your current company's web site.
Tailor the above examples to your individual knowledge, skills, and abilities; do not say that you can do something if you really can't. Do NOT lie on a cover letter or resumé, because you will be caught sooner or later.
== Keep your skeletons in the closet ==
Do not include any personality quirks or bad habits, unless an interviewer asks if you've been convicted of a felony, or something serious like that. Otherwise, leave out the small stuff. If you sometimes drag your feet when beginning a project, or perhaps have shown up late a few times over many years at your current workplace, don't mention it. Give him a spotless record with only positives, because that's what he wants.
== Proofread, proofread, proofread ==
When you are done tossing around words and sentences, save what you've done and take a break. Your brain needs a rest after extended, intense concentration. It's like pulling into a rest stop during a long drive - you need to stretch periodically, and so does your grey matter. Go have a snack, play with the cat, or if it's late, go to sleep. Then come back when you're refreshed and ready to tackle this last bit.
Proofread your cover letter, edit, proofread again, then have a trusted friend read it one more time to ensure perfection. If no one can help, hire a professional copy writer/editor. Yes, it's that important. No matter what successes you've had previously, bad spelling, grammar, syntax, and punctuation may lead a hiring manager to wonder if you really want this job. If you cut corners in your cover letter, she may think you do the same at the job, and no one wants an employee who tends toward laziness. Proofread.
== Summary ==
Remember, this is your chance to create a document that makes you outshine everyone else who wants that job. You must show yourself in the best light, so forget the humility and tell your hiring audience all about your accomplishments. Don't forget the high-grade paper, the smudge-free print, and the proofreading. This is all part of showing your professionalism. If you give the hiring manager no reason to doubt your abilities, you've made a good cover letter. Be proud!