The bad news is that writing a killer query is hard. The good news is that writing a killer query is both art and craft. This means there’s a technique or strategy that you can learn.
And learn you must because it doesn’t matter how beautifully written, how heart-poundingly suspenseful, how knee-buckling funny your manuscript is, no editor or agent is going to see it until they’ve been blown away by your initial query pitch.
I know, I know, you’ve spent months beavering away at your great novel and now you just want someone to read it, love it, publish it. But first, you’ve got to hook ‘em with a couple of paragraphs.
It may seem crazy but no more bizarre than trying to flog a screenplay. Those scriptwriters have to verbally pitch their written words!
So, suck it up. It can be done without too much hair pulling.
A killer query is:
• An advertisement for your book
• Brief
• Punchy
• Personalized for a specific editor or agent
• Crafted to hook the reader’s interest
• Delivered in a writing style that suits the book
• Designed to leave the reader wanting more.
THE BASIC ELEMENTS
(Note: examples below are from the pitch I used for my paranormal sci-fi novel, UnnaturalStates which triggered a number of requests for the full manuscript)

UnnaturalStates: John & Harry Battling
First paragraph:
• opening line pitch: two sentences or so that hooks reader’s interest, written in the style of the book.
(e.g., What astounding secret legacy, resurrected from a controversial divine relic, is being shrouded by the stigmatic, pop-evangelist John the Apostle?)
Second paragraph:
• three to five sentences providing more information about the main character and his/her character arc, the central plot and the length and style of the book.
Already revered and reviled for his powers of song and healing, the charismatic superstar’s mythic life tragically unravels after three strangers infiltrate his west-coast Passion Ministry during its intensely anticipated Easter concert week. Their combined inquiries trigger revelation, ruin and murder.
Merging religious and paranormal phenomena with bio-technology and the ethics of cloning, Thy Will Be Done–a 100,000-word suspense novel–explores the devastating consequences fused from the collision between today’s spiritual emptiness and scientific abundance.
Third paragraph:
• two to three sentences about you, such as your qualifications, the reason for writing the book, the possible audience/markets for the book and why you are the one to write and to promote it.
My publishing credits include eight mysteries, two optioned screenplays and one optioned television series. A shameless self-promoter, I attend signings and conferences and maintain my own web site. I am also a member of the Crime Writers of Canada (Vice-President) and of Sisters in Crime.
Fourth paragraph:
• two sentences to ask if they wish to receive sample chapters or the entire manuscript and to thank them for their kind consideration.
Now, sign it. Send it off. Go on to the next one!