WHEN NORMAL IS BORING
Act One in a screenplay comprises the first quarter or so of the script and often it is described as relating the "normal world" of your protagonist before they are plunged into the new world of the main conflict.
For example, in a story about a teacher who, upon retiring, decides to return to their long-forgotten dream of climbing Mt. Everest, the first act would show their rather settled life, their retirement party, then boredom setting in, until finally at the end of Act I, perusing an old journal of theirs awakens their dream again (the inciting incident).
The hidden danger in that story, and many first acts, is that often the protagonist's normal world isn't very interesting. We don't want to be bored for 20 minutes until the interesting part of the story starts. At the same time, what follows is more dramatic if we understand how far out of their depth the protagonist is when they find themselves in the new circumstances.
SOLUTION 1: BOOKENDS
There are several solutions to this problem. The first is to use a bookend structure. You start the story with the teacher stuck halfway up the mountain in peril, and then flash back to the beginning, or you can distribute several flashbacks throughout the script.
"Titanic" used the bookend structure, with the old Rose at the start and end, and the story of the young Rose in the middle.
SOLUTION 2: FORESHADOWING
Another option is to foreshadow what is to come. For instance, in the story of a violent home invasion, you might show the home of the family being observed by persons unknown while you establish the members of the family and what their life is like.
In disaster movies, the foreshadowing often is something like a minor earthquake (in advance of The Big One) or a TV weather person making a by-the-way comment about a storm taking an unusual turn, or a kid with a telescope being teased when he thinks he's spotting something strange about the comet that's going by.
SOLUTION 3: DISTRACTION THROUGH ACTION
The James Bond movies had a pattern of showing Bond in the exciting, action-packed finale of a case we didn't know about. Then he would go and get his next assignment. Having already had an adrenalin fix, the audience would be patient while the next case was set up. This could be called distraction through unrelated action.
SOLUTION 4: REVEALING IN REAL TIME
A more challenging but often effective solution is to kick off with the inciting incident and in the course of the story reveal what the protagonist's normal life was like. That is, reveal their normal situation in the story's real time rather than in flashbacks.
For example, in the story of a man who gets kidnapped, normally you would show his family life and maybe his work relationships first, then the inciting incident is his kidnapping. Alternatively, you could start with the kidnapping, and reveal the relationships via how the people in his life react and what they do to try to help him.
GO BACK AND FIX IT
Sometimes writers get stuck trying to come up with the perfect opening scenes and keep rewriting them instead of moving forward.
Don't get hung up on trying to come up with the perfect first act in your first draft. Do the best you can and keep writing through to the end.
When you get ready to do the next draft, ask yourself whether your first act will get and keep the attention of the audience; if not, try the remedies above.
