I will routinely advise new writers to make sure their cover letters are professional in tone. All additional correspondence with an editor should be similarly professional.

There are a few other details regarding a cover letter that may be of interest. For instance, if you can't say what needs to be said in one page, you need to say it again. It is bad form to send a cover letter that is longer than one page. The person you are sending the cover letter to may make a judgement about your potential based on the first 20 seconds of your cover letter. If your cover letter is not concise and professional, the letter may be put aside without further consideration. One thing that may help in keeping your letter concise is to work at keeping your sentences short. Twelve to fifteen words should be the target word count for sentences in your cover letter.

There are also certain fonts that you can use to instill a contemporary feeling (such as Arial and Verdana) while there are more traditional fonts that may be used in other instances (such as Times New Roman). Avoid the use of obscure font choices, you want your letter to be readable and the use of these fonts or extensive special formatting can actually detract from your presentation.

When writing your letter make sure to avoid the use of words and phrases that aren't routinely found in daily conversation. Just because your letter is professional doesn't mean that it morphs into something that is less than conversational. You should be able to read your letter out loud and have it sound very much like your normal language and vocabulary use.

Try to take a 'less is more' approach to your cover letter. As mentioned earlier choose one font, keep it simple, no more than one page and use black ink on clean white paper. If the color or font is distracting to the reader it is less likely to gain a fair hearing. Unlike most writing, cover letter writing relies on clarity and that means being concise.

Beyond the construction of the letter, you should include a paragraph dedicated to the summary of your literary work. You should also include a marketing summary that simply states why your work is unique and marketable.

Your letter should express appreciation to the publisher for the time they spend with your manuscript.

One final tip is to be patient. Allow the material to go through proper channels. It can take a few weeks or as much as a year to receive correspondence from the publisher. If you contact them before the end of their stated consideration timeframe, it may decrease your chances of acceptance.