Every book needs a logline.

It's the one or maybe two sentences that introduces your story to a potential reader with the main conflict

And it may be the hardest thing you write.  Taking your 70,000 word manuscript and boiling it down to it's essence, while at the same time enticing and intriguing your readers is down right difficult. 

The key is to not tell the story, but sell the story.

Note:  A logline is not a tag line.  A tag line is one line, usually found on your cover with the theme of the book. Here's mine for my first book, Ruby Red to demonstrate the difference.

Tagline: Sometimes you find love only after you have lost everything else. 

Logline: When she discovers her bank accounts drained, spoilt socialite Ali Stinson has two choices, admit defeat or accept the help of the one man she might lose her heart to. Sam Freemont moved to LA for a fresh start, not to meet the woman of his dreams. Will his secret destroy the delicate trust she has placed in him or will love conquer all?

As you can see, my logline still needs refining. 

Just like the logline itself, tips for writing one are in depth and I could not do you justice with a few little quips. 

For a step by step guide, check out this resource. (see comment for link)

What's your log line?