To start we need—as any starting screenplay needs—three things:

• a good Initial Idea,
• a solid Premise, and
• a clearly defined Genre. 

For this example let's make a "Romantic Comedy" (that'd be its Genre) about "A Guy Who Falls In Love With A Girl Passing By On A Bus" (that'd be the Initial Idea) and proves that "Impulsive Love Leads To Happiness" (there's the Premise).

Now we can start working on our Storyform by Delineating our Genre (look at the Chapter about "Genre And The Dramatica Domains").  A Romantic Comedy usually has a SS Domain of Physics.  That'd give us an OS Domain of Psychology.  Let's mark it.

(CONTINUED)