Break your script down. The more detailed your storyboard, the easier the filming process will be later, so be as thorough as possible. On a board or a big piece of paper, post notes or make a diagram of how you see the film developing. Define the major turning points of your story. Mark all the scenes. Focus on shots, camera angles, and every other detail that can help the story move forward, create emotion in the audience, or assist the cast and crew with their work.
Show, do not tell. The basic principle of screenwriting applies to storyboarding as well. Picture all your scenes and visualize different camera movements, rather than explaining the information that is in your head. Writing long descriptions of how you want this scene to be or how you want the director of photography to work on that shot will only confuse everybody. Everything in film needs to show pictures, rather than describe them. Focus on getting your point across in just a few words. Less is more in storyboarding, and even though your outline is more helpful when it breaks the script down into smaller pieces, when too much writing is involved in every piece, the purpose of a detailed storyboard is defeated.
Put your storyboard to the test. Not everyone in your team can be thinking in the same way, and not everyone will find your storyboard helpful. But film-making is primarily team work, and a storyboard needs to communicate information and be understood by every member of the group. Take the time to test your storyboard by presenting it to your cast and crew. Ask them if they understand how you see the film developing. Make room for different opinions and suggestions. Make adjustments accordingly.