Write a "tag line" for your graphic novel, which conveys the story's concept in a single short sentence.
Expand the tag line into a "log line" by writing a sentence explaining the story's beginning, two sentences for the middle, and another single sentence for the ending.
Write a synopsis of the graphic novel by expanding each sentence in the log line into a full paragraph. The finished synopsis still shouldn't be longer than a single sheet of paper.
Take each paragraph in the synopsis and expand it to a fill a full sheet of paper, but no more. This is the first stage of your graphic novel's outline.
Proofread the outline thoroughly, and go back through each stage of the template, making any necessary adjustments to the story. Begin with the tag line and work forward from there until you have a second draft of the four page outline.
Write biographies for each of the characters that were important enough to warrant a mention in the outline. Include details of their childhood, their physical appearance, family history, what they do for a living, how they spend their free time and what their motivation is within the graphic novel's story. The biography should cover their lives up until the point at which the graphic novel's story begins.
Rewrite the outline based on any changes that have surfaced after writing the character biographies, and expand each page as much as you like into a "step outline." This step outline should cover everything that happens within the entire story, but without including any dialogue. Keep going back over the whole template, making adjustments as the story and characters evolve within the step outline.
Write the first draft of the graphic novel's script, following the step outline closely.