1. Do not fuck with the Assistant. Do not even THINK of fucking with the Assistant. Do not send the Agent emails insisting the Assistant has rejected you because s/he is a moron, is underage, cannot read, or could not recognize a work of Great Literature if someone hit her/him in the face with it. The Assistant is, in all probability, much smarter, much more widely read, and WAY cuter than you. Be polite.
2. Do not submit your book unless it is finished. By "finished" we mean "in this very moment of the here and now."
3. No one is fooled by obsequiousness in this office. But a little charm goes a loooooooong way.
4. The Assistant would prefer not to receive photographs of you: in the nude, on vacation, on your deathbed, next to a picture of an international supermodel/Leonardo DiCaprio with the suggestion that s/he should portray you in the film version of your life. The Assistant is also not interested in photographs of Princess Diana even if they prove JFK killed her, but thank you anyway.
5. Do not send the Assistant your tired, your poor, your huddled masses. The Assistant is not Ellis Island. The Assistant isn't interested unless it's GOOD.
6. It ain't the Assistant's fault no one is publishing you, honey.
7. FOR GOD'S SAKE USE A NORMAL FONT AND BY NORMAL WE DO NOT MEAN WINGDINGS
8. It is the Assistant's job to
crush your dreams/spit on your hopes/make you cry pass good things on to the Agent. It is not the Assistant's job to tell you how to write a book, dole out the milk of human kindness, or hold your little Author-hands. Don't ask.
9. Certainly you may buck the conventions of the query letter if your work is too amazing/revolutionary/brilliant to be summarized. Why don't you also try applying for jobs without a résumé, using only your psychic powers. Let us know how that works out for you.
10. Don't write your query letter from the point of view of your main character. Just don't. It never works. Especially if your main character is a SERIAL KILLER CONFIDENTIAL TO THAT DUDE IF YOU EVER EMAIL US AGAIN WE ARE SENDING YOUR HOME ADDRESS TO THE POLICE.