Basics for all correspondence:

Individualize
There are similar elements to job search letters, but each letter should be individually tailored and targeted to the recipient. There is no such thing as an effective "form letter" in a job search. You know when you get a form letter; a prospective employer knows too. A letter that looks like it could have been randomly sent to any employer is a good candidate for the employer's "no" pile. 

Make your purpose clear
Don't make an employer guess why you are writing or what you are writing about. In choosing your words, think about the purpose of your letter and details of your individual circumstances. For example, if you make a telephone call to an employer prior to sending an email, it makes sense for your email to refer to the telephone call. If you must respond to an employer's email to you, read it carefully to draft an appropriate response. 

Tell the employer what you'll do for the organization, not what the organization can do for you.
Saying, "I really want this job because it will give me great experience," is not a sell to an employer. Of course the job will give you (or someone else) great experience. It just makes you sound "all-about-me." Instead, tell the employer what you have to offer. Be specific and realistic; as in, "I have strong organizational skills that I developed and demonstrated when I was event chair for my club." Don't use hyperbole; as in, "I will immediately contribute to higher profitability on my first day on the job." 

Edit
Grammar, spelling and punctuation should be error-free; wording should be clear, concise and business-like; avoid gimmicky language and slang terms. 

Don't rely on spell check alone
Spell check won't let you know that you've used manger instead of manager, perspective instead of prospective, left the "l" out of public, and so on. (All mistakes we've seen plenty of times.) 

Be yourself
Be your formal, business-like self, but express yourself in a manner that is natural to you. Avoid too much borrowing of language from sample letters and friends' letters. Excessively flowery language or using complicated words won't make you sound smarter; it could make you sound silly. Use good examples as inspiration, but don't copy. 

Record-keeping
Retain copies of every email you send and receive; mark your calendar for any appropriate follow-up.

Common Sections in Application Letters

As for the actual content and organization of the paragraphs within the application letter, consider the following common approaches. 

Introductory paragraph. That first paragraph of the application letter is the most important; it sets everything up-the tone, focus, your most important qualification. A typical problem in the introductory paragraph involves diving directly into work and educational experience. Bad idea! A better idea is to do something like the following:
- State the purpose of the letter to inquire about an employment opportunity.
- Indicate the source of your information about the job-newspaper advertisement, a personal contact, or other.
- State one eye-catching, attention-getting thing about yourself in relation to the job or to the employer that will cause the reader to want to continue.

And you try to do all things like these in the space of very short paragraph, no more than 4 to 5 lines of the standard business letter. (And certainly, please don't think of these as the "right" or the "only" things to put in the introduction to an application letter.) 

Main body paragraphs. In the main parts of the application letter, you present your work experience, education, training whatever makes that connection between you and the job you are seeking. Remember that this is the most important job you have to do in this letter to enable the reader see the match between your qualifications and the requirements for the job. 

There are two common ways to present this information: 
Functional approach - This one presents education in one section, and work experience in the other. If there were military experience, that might go in another section. Whichever of these section has your best stuff should come first, after the introduction.
Thematic approach - This one divides experience and education into groups such as "management," "technical," "financial," and so on and then discusses your work and education related to them in separate paragraphs.

Another section worth considering for the main body of the application letter is one in which you discuss your goals, objectives the focus of your career what you are doing professionally. A paragraph like this is particularly good for people just starting their careers, when there is not much to put in the letter. Of course, be careful about loading a paragraph like this with "sweet nothings." For example, "I am seeking a challenging, rewarding career with a dynamic upscale company where I will have ample room for professional and personal growth"-come on! give us a break! Might as well say, "I want to be happy, well-paid, and well-fed." 

Closing paragraph. In the last paragraph of the application letter, you can indicate how the prospective employer can get in touch with you and when are the best times for an interview. This is the place to urge that prospective employer to contact you to arrange an interview. 

Common Problems in Application Letters 
- Readability and white space--Are there any dense paragraphs over 8 lines? Are there comfortable 1-inch to 1.5-inch margins all the way around the letter? Is there adequate spacing between paragraph and between the components of the letter?
- Page fill--Is the letter placed on the page nicely: not crammed at the top one-half of the page; not spilling over to a second page by only three or four lines?
- General neatness, professional-looking quality--Is the letter on good quality paper, and is the copy clean and free of smudges and erasures?
- Proper use of the business-letter format--Have you set up the letter in one of the standard business-letter formats? (See the references earlier in this chapter.)
- Overt, direct indication of the connection between your background and the requirements of the job--Do you emphasize this connection?
- A good upbeat, positive tone--Is the tone of your letter bright and positive? Does it avoid sounding overly aggressive, brash, over-confident (unless that is really the tone you want)? Does your letter avoid the opposite problem of sounding stiff, overly reserved, stand-offish, blase, indifferent?
- A good introduction--Does your introduction establish the purpose of the letter? Does it avoid diving directly into the details of your work and educational experience? Do you present one little compelling detail about yourself that will cause the reader to want to keep reading?
- A good balance between brevity and details--Does your letter avoid becoming too detailed (making readers less inclined to read thoroughly)? Does your letter avoid the opposite extreme of being so general that it could refer to practically anybody?
- Lots of specifics (dates, numbers, names, etc.)--Does your letter present plenty of specific detail but without making the letter too densely detailed? Do you present hard factual detail (numbers, dates, proper names) that make you stand out as an individual?
- A minimum of information that is simply your opinion of yourself--Do you avoid over-reliance on information that is simply your opinions about yourself. For example, instead of saying that you "work well with others," do you cite work experience that proves that fact but without actually stating it?
- Grammar, spelling, usage--And of course, does your letter use correct grammar, usage, and spelling?

Written communication, usually by email, serves many purposes in a job search. In a thorough job search, you will write many types of letters. Cover letters, which accompany and introduce your resume, are the ones you may hear about most, but are not the only letters you will need. Letters also precede, follow-up and confirm verbal conversations, so they serve as a record and reminder of interactions, as well as evidence of your communication skills.