Writing a book is fun. Writing a query letter is stressful. In your book, you can add layers of backstory and extra pages to let your full story flow. In a query letter, you basically have four tiny paragraphs to say "PICK ME! PICK ME!"
Holy crap, I'm having grade-school playground flashbacks.
So what's the best plan of attack to creating a pitch perfect query letter? I'm a firm believer in learning by reading query letters that actually landed agents. Our Guide to Literary Agents editor Chuck Sambuchino (who speaks on this topic at conferences regularly) has inside connections to agents who share with him actual query letters that landed writers agents. These include commentary from the signing agent that explains why it worked.
Check out the Successful Queries series here and take notes. You spend countless hours on your book. It's worth investing time in your query letter. If you handle it correctly you won't have to yell "PICK ME!" so loudly.
Here are a few recent Successful Queries from Chuck's GLA blog:
Agent Roseanne Wells and ''Dumbemployed''
Agent Lauren MacLeod and ''Real Mermaids Don't Wear Toe Rings''
Agent Elisabeth Weed and ''The Arrivals''