Plot Point I: Opening & Closing Images
First off, I'd decide on what the opening & closing images are once you know what the story is that you're telling. So, at least a solid outline should be written or a first draft before you tackle this baby.
The opening image is your strongest piece of visual storytelling because it sets up the protagonist's journey. It begins to ask the question:
How will the hero be changed by the telling of this story?
It's generally an emotional image that can cover a lot of ground in terms of drawing the viewer into the story immediately.
It does a lot of work setting up the world of the story, place, time, what's at stake for the protagonist, what the protagonist will learn and what their emotional journey will be and hints at the major conflict of the story.
But it only does this if it's a great opening image and crafted in the writing as specific and meaningful.
To get some really solid ideas about great opening and closing images, I'd start watching films you love...That move you, that get you right in the heart immediately. Or films that throw you into the action so rapidly, that you don't have time to think, you just get on the ride and hope for the best...lol.
Joseph Campbell talks a lot about the hero's journey in The Power of Myth, so that might be a great place to start reading and getting some more ideas about visual storytelling of the hero's journey.
Well, the opening image is a metaphor for that journey.
For example, in "The Color Purple", we see a wide shot of a field of golden wheat. As the colors intensify, we hear two little girls singing a lullaby about being sisters "who will never part." They are all alone in this wide field of gold as if they are the only two people on earth. Watching that image, you know, in your heart, that they will most definitely be torn apart by this big, beautiful world.
And that is exactly what the entire film is about. How these two little girls, are torn from home and flung to distant parts of the earth where they spend the rest of their lives trying to find each other again and come back to this field.
And of course, at the end of the movie. Celie is sitting on that same porch watching the field, when she sees her sister coming across the plains 50 years later. The movie ends with the two old ladies sitting in the field singing that lullaby. Because although they were parted for a while, they are now back to together again. And that's the closing image.