Simplify your pitch. A documentary film obviously covers a lot of information, and it might be hard to fit everything in one page. You have to capture the interest of people who don't have a lot of time on their hands and probably read pages like this every day. They want to see something short and to the point. Begin with your idea, and use paragraphs for each specific area for such things as location, talent, interest and experience.
Choose a documentary subject, or if you've already researched one fully, start with a brief description, no more than a few sentences. For example, you may know or have heard about a family who raises sea otters and then releases them into the ocean. Assuming you want to tackle this project, write about the family, what they do, where they are and the animals under their care.
Explain why you're qualified to write about your idea in the next paragraph. In the case of the family caring for sea otters, you might want to talk about your experience working with these animals, or education you may have had in marine biology or veterinary science. Your qualifications are very important to the people reading your pitch. They want to know the project is in good hands. You're not trying to sell yourself, however, so keep the self-praise to a paragraph at most.
Explain the emotional elements of the project. Using the sea otter scenario, you should decide if this film will be a heart-tugging drama about the plight of sea otters today, or a light-hearted, cuddly look at sea otters being playful as they're home-grown.
Decide if you want to use a narrator, and the celebrity voice you can arrange. If you have a pleasant enough voice, you could offer to call the action yourself. If you have some actors in mind that would like to appear in the film, you can list those as well.
Write a list of the technical equipment and other considerations that would be needed to film. Sea otters spend a great deal of time in water, so you might need extensive underwater camera equipment, for example.
Conclude your pitch by writing a paragraph about the conclusions that could be drawn from your documentary, and the reasons it could be very popular and well received. For example, audiences may flock to theaters to watch lovable sea otter pups at play, and could appreciate the often-treacherous lives they lead. This appreciation could then lead to global concern and outreach to organizations and movements that fight against sea otter hunting.
Revise and edit your pitch once you have everything written down. No decent film professional will look twice at a documentary pitch filled with typographical errors or bad grammar.