Telling me how to do something never works for me. Whatever my natural inclination is will override what I'm taught. Telling me why something is done will give me a new perspective and allow me to change my set ways.
We freeze at writing the synopsis. How do we boil 400 pages down to 2-3? That's one way of looking at a synopsis, but not what I see it as. It's just another format to tell the story you love so much, you wrote those 400 pages. (I love writing the synopsis now. I'll take every opportunity to tell my story.)
A synopsis is important. It shows you have a complete story with a beginning, middle and end. That is just one function. The goal is to get the agent to ask to see more, to see your actual writing, your voice.
I've heard that the synopsis doesn't need to include your voice. I disagree, but I will qualify that. It doesn't need to include the voice you used for the story, but it does have to include your voice, AKA your excitement and love for your story. That is contagious and will motivate the agent to ask to see more.
Writing the synopsis is like writing the book, and you can use the same techniques you would to plot it out. If you are a plotter or a hybrid, this part is easy for you. If you pants it all the way, I'll offer some suggestions.
The most important part of the story, and therefore your synopsis, is not boiling your story into one sentence. It is the initial idea you had, maybe even the idea of an idea. Think back to that initial idea. Don't think of the synopsis. Think of that idea. Let it wrap around your heart and strengthen you. Let it bring back the time when the words screamed to be let out. It could have been a month ago or several years. Try to think back to that time. You aren't writing a synopsis. You are writing the story that idea generates.
Now, if we were writing a book, one technique is to brainstorm scenes. You already wrote those scenes. I want you to brainstorm what you love about the story. Just list everything. What things made you stop and think "Damn, I can't believe I wrote that?" What things kept you butt in the chair, even when your muse decided to get a tan at the beach? What sweet nothings did he whisper in your ear? Just write it all down.
Look at that list and cross out everything that doesn't have to do with the main storyline. I'm sure it was very interesting when your heroine turned into a seagull, but if that isn't part of the main storyline, it goes. Look at the list again and cross out anything not vital to the main storyline. Can you tell the story without mentioning something or does it become a completely different story?
Take what you have and put them in chronological order. That's the skeleton of your story. Fill in the key points that makes the story flow. Guess what? You have now told your story in a different format, otherwise known as a synopsis.
This isn't a synopsis that just retells your story. It shows your heart, your excitement, in essence your voice. It will get the agent to request more pages.
Why do we write a synopsis? Because we love our story. Because we want to share that story. Because that love is infectious and will get others to read our story.
Isn't that why we became writers- to tell a story and have others read it? So tell your story. Don't freeze. Don't boil 400 words down to 2-3. Do what you do best, tell a story.