Let a script breathe? Come on. A script isn’t human (not before your shoot it) so how can it breathe?
Think of it as a child, your child. You must have at least nine months of pregnancy to have a child. There is no instant child. The same is with a script. There is no time limit when you write it unless you are professional and someone hires you to write it. For a freelance writer it can take months or years to have one ready and even then it is not finished until the film is shot and edited.
You started writing knowing – more or less – what is the concept, where you are heading, what is that you want to express. The urge that made you put everything else aside and dedicate your life to writing the script.
You finally managed to finish a draft of the script - all 90 or 100 pages of it. You have now earned the right to sit back and relax. What now? What would be the next step? You probably can not wait to open the window and shout to the world "I did it!! My script is finished!!"
My advise – Don't. Don't print it and don't distribute free copies to family members and close friends. Why? because your creation is still a long way from being completed. Now you got to put it aside for at least a month or even more. Try to put it out of your mind as if you never wrote it. Let the script breathe for one month before you look at it again. Now read it. You will then realize that your first draft is not exactly a masterpiece. Scenes and dialogues have to be changed or deleted in whole or partly. Some of them are pure shit. You can't believe that you were the one to create them. Why does it happen after a month? The lapse of time gives us a much better perspective of the script. A distance. You were detached from it for a certain period and can now be much more realistic. The first draft is written from the guts. All your feelings – and fewer thoughts – are in it.
You are now ready to start rewriting the 2nd draft which is very painful process to a writer. Writing the 1st draft you fell in love with your words and now you realize that in order to make it a better script you got to be merciless and delete scenes and dialogues. I had a 100 pages script which I thought – after the 1st draft – was great. 30 pages were deleted when I worked on the 2nd draft to be replaced by other 10 pages. As a result the script looked much better and tighter.
How many drafts should you write ? No one can tell you that because the rewriting goes on even during the shooting of the film. But you still have a very long way to go before your script reaches the shooting stage. In Hollywood each draft of the script has a different color. In some scripts they ran out of colors. But do not let this discourage you because the roads from the 2nd draft to the other ones are much easier. It is a matter of fine tuning – just like a car.