After you conceive the idea, the story that emerges from that idea needs intense logical and emotional development, which you should write out in 2 pages, double spaced.
In this process, don't be afraid to use the wastebasket or the eraser.
At the same time, don't be too quick to discard your first impression of anything. First impressions, or first ideas that come to your head originate from your instincts and subconscious, which is the bedrock of your creativity.
When logic takes over your initial instinct, beware. Logic can quickly make you second guess, and dull your story.
Here, you don't have the scenes yet. For these 2 pages you'll just have the broad beginning, middle, and end, to see what you've got.
1. The Characters
2. The Location
3. The Beginning (Act One)
Create Conflict
The cliche that "opposites attract" may not be true in real life. But in movies, opposites translate into dramatic conflict in the story, and every aspect of your lead character's lives.
This should give me an excellent beginning
4. The Middle (Act Two)
The Complications
The beginning should lay the groundwork and foundation for all the complications to come.
Drama = somebody going against the law, against the norm, against society, against themselves, against God, etc.
Later during the step outline phase, you'll include more characters and events as you would throw logs in someone's path to stop or impede their progress. Conflict!
Act 2 usually ends with "The Big Gloom." This occurs inevitably at the end of Act 2, around page 80, where the protagonist is furthest from achieving his goal.
5. The End (Act Three)
It's always good to have the third act in mind as soon after the idea as possible.
Generally, have an ending that is either happy or sad. Remember extremes? Don't end your movie with sort of happy or sort of sad.
A great ending should always produce emotion. Emotion is the real gold at the end of the movie rainbow.