disciplined creativity

I've been told that there comes a time when one can be creative on demand. Sadly, I have not reached that point yet. When writing the screenplay, I know where to go, but not how to get there. It's like there's pit stops I need to take that I didn't take in mind when I planned the trip.
This is a setback because I've gotten over my self discipline issues, but now I don't know how to make the right idea come to me.

Brooding of you,
Mr. Jordan