There are websites FULL of advice on how to write the perfect query, written by people far more qualified than I. They were a big help to me while writing MY query. My advice is for what you should do AFTER you’ve got your query perfected. While I’m not a famous, published author, my query DID land me an agent, so take it for what it’s worth.
Here it is – FOLLOW THE RULES.
I know that sounds like a big, “duh”, but I can’t tell you how many agencies complain about authors disregarding the submission guidelines and just hitting the “SEND” button. When I began sending out my query, my goal was to do 10 each week. That may not seem like a lot, but since every agent want’s something different – it was very time consuming. If an agency wanted the first 10 pages, they got the first ten pages and no more, no less. If they were looking for Young Adult novels with a dark edge, I DIDN’T send a query, since mine is not that at all. Seriously, why waste their time AND mine?
Occasionally, when I was in too good of a mood to be depressed, I’d check out http://arcaedia.livejournal.com/ She posts weekly stats on how many queries she’s received and how many manuscripts she’s requested. Last week it was 203 read, ONE manuscript requested. Probably half of the queries she read could be discounted immediately for NOT following her submission guidelines or being outside the scope of what she was looking for.
Do your work, and follow the rules. It will speed up the process and you’ll find an agent before you know it!