Get your idea for your book into a 'hook' or 'logline'.

Don't start writing until you've got your idea nice and tight in one sentence - packing an ironic pop!
No really, I wouldn't if I were you. I have, but when you start flabby, it's like loosely packed clay on the potter's wheel. You press the pedal and you've got shit flying in all directions.
I  won't let my writers start writing until we know we have a solid, hard-working, great - and yes that means commercially viable - idea for a story. You leave The Classic Course with wonderment and irony locked and locked into your story idea. You start the Ninety Day Novel with seven days to get this tight. Honestly, a great idea can take years, so this is the hardest work you'll do on the course. Delivering the content of a novel is easy, once you've got an idea you can't wait to write and then you can allow yourself this Peter Pan moment:

'“How clever I am!” he crowed rapturously, “oh, the cleverness of me!”

It is humiliating to have to confess that this conceit of Peter was one of his most fascinating qualities. To put it with brutal frankness, there never was a cockier boy.'

(JM Barrie: Peter Pan and Wendy 1911)

What do I mean by irony? Well, it's not 'a black fly in your Chardonnay' or 'rain on your wedding day'. That's just bad luck. What's ironic about Alanis Morrissette's song is that it's not ironic.
'The expression of one's meaning by using language that normally signifies the opposite;
  • a state of affairs or an event that seems deliberately contrary to what one expects and is often wryly amusing as a result.
     
  • a literary technique, originally used in Greek tragedy, by which the full significance of a character's words or actions is clear to the audience or reader although unknown to the character.'
     
One notion in conflict with another SPRINGLOADS the idea and traps the reader inside the confection of your fiction, rattling between point and counterpoint immediately.
The result is the reader goes - WHAT! And that's how we want to keep them from start to finish of their reading experience.
  • Policeman turns to crime
  • Teacher learns
    lesson
    from students.
  • Man
    who doesn't like women, becomes a woman, for the love of a woman.
If you can load your title with irony too, you're ahead of the game and can leave the elevator without a pitch. I like 'Judge on Trial' by Ivan Klima, and 'Beware of Pity' by Stefan Zweig.  'The Good Soldier' is good when you know the context. Titles that defy our expectations like 'Love In the Time of Cholera' work well. After two limp novels, I worked hard to make sure my third hit the mark and loaded my title with irony 'Becoming Strangers' with the idea being that a dying man found new life. 

The irony is stowed in the FLAW which sets up the novel (you can find out more about the big story structure on the course - see the Kritikme Five F's) and in a children's classic  this is a COSMIC FLAW which delivers 'cosmic irony' the disparity between what humans desire and what the world actually serves them. Mostly, in the classics, this is the chosen kid who's an orphan. This is an irony of fate. No one's fault. The big funny not so haha from on high. A former athlete who is now paralyzed is an example of irony of fate. Beethoven, one of the world’s greatest composers lost his hearing.
Because a novel is a moral journey, as well as all kinds of other adventures, a cosmic flaw, a twist of fate, locks in sympathy and hope and at the end of the day a reader reads on hope.

It's pretty simple. Your idea should ring clear as a bell. Make sure you're packing irony.
In my bluffer's visual, the balloon of the idea rises, with the pin that pricks it underneath - poised to make you and your comfortable ideas, dear reader, go POP!

I woke early the morning I wrote this with a sudden insight as to how to create a tool that could help my writers generate their logline. It has taken me many many years to slim down my understanding of how the hook hooks to get this down to a few steps and serve it up on a plate.
The Kritikme Hook tool is now installed inside our creative writing courses at Kritikme.com and all writers will be pre-approved for take off before writing.
I'll review your hook with you, one by one, and when we're terribly over-excited by it, you'll be good to go. (And I wish I'd been held back from starting a novel a few times in the past until I had a hook with bite.)