Early in the process, you will probably want to make an outline that charts the major events in your story. This will ensure that your story has enough turning points and escalation, and it will serve as a guide to follow on your early drafts. An easy way to do this is to figure out the five major events of your story and write them down in their simplest form. It won't make sense to anyone except you, but that's okay. Here's how it might look for Die Hard:
Inciting incident: Terrorists storm the building
Plot point 1: Terrorists kill the head of the corporation
Midpoint: McClane captures attention of the cops
Plot point 2: Terrorists open the vault
Climax: McClane faces off with the terrorist leader
If you want to take this just a bit further, you can make a story map (a Gotham Writers' Workshop invention). The story map includes the five major events and gives just a hint of how these events are connected. This will help you get a general sense of the story's progression. Here's how a story map might look for Die Hard:
ACT I
John McClane, a wisecracking New York City cop, has come to L.A. to visit his estranged wife. They attend a Christmas party for the Nakatomi Corporation, where his wife is an executive.
Inciting incident: A team of European terrorists storm the building. The terrorists take everyone in the building hostage, except McClane, who lurks unseen. Hans Gruber, the suave terrorist leader, requests that Mr. Takagi, the president, reveal the codes for a vault containing millions in bonds.
Plot point 1: When Takagi refuses, Gruber shoots him in the head. McClane realizes the terrorists are killers and he must stop them.
ACT II
McClane repeatedly tries to signal to authorities what is going on, without success. Meanwhile, the terrorists get wind of McClane's presence and come after him.
Midpoint: McClane heaves the body of a dead terrorist from a window onto a cop car. Realizing something is up, the cop calls for reinforcements.
The LAPD and FBI swarm the building, but the terrorists prevent them from entering. McClane continues fighting the terrorists from within. The terrorists succeed in cracking six of the seven locks on the vault.
Plot point 2: When the FBI cuts off the building's power, the seventh lock releases, opening the vault. After seizing the money, the terrorists can move to the final stage of the plan—masking their escape with a massive explosion that will kill all the hostages. McClane, still the only non-hostage in the building, is exhausted and injured, not sure how much steam he's got left.
ACT III
When Gruber learns that one of the hostages is McClane's wife, he seizes her as protection against McClane.
Climax: McClane confronts Gruber in the vault. He manages to save his wife and send Gruber hurtling out a high window to his death.
The terrorist threat is over, the hostages safe, and McClane is reunited with his wife.
Stepping-Stone: Story Map
List the five major events of your movie in their simplest form.
Then, using the five major events as guideposts, create a story map. Your story map doesn't have to look exactly like the one above, but you should keep it brief and focused. Try to make it fit on one page. The major events may well change during the writing process, but this will give you a good starting point.