I don’t have to do a lot of pitching these days, as most of my work is word-of-mouth or repeat business, but the old-fashioned query letter is still a great tool when I do pitch. I find the examples in Writer’s Market to be a good but limited (sorry!) start; the query letters that have the greatest success rate for me are the ones that follow the same basic format but are much less formal and more conversational.
Editors want to see two things: 1) that you can write in their voice, not a stiff “business formal” one, and 2) that you’re a real live human. Do that and your pitches will succeed more often than not.
Rachel Kaufman blogs about media careers at http://mediabistro.com/mediajobsdaily. She’s also written about food, biology, real estate, and almost every other subject under the sun for The Washington Post, National Geographic News, CNNMoney.com and others. Her portfolio appears at http://readwriterachel.com.