One of the first considerations in the planning phase is choosing a subject and writing a script. You may hire a writer to construct the script or construct it yourself. Whatever you choose to do, thoroughly read the script before moving on to the next phase to make sure it matches your directorial vision. If you are the writer, be prepared to make quick changes as production enters later changes.
The script should not be limited to the lines that actors will say. A good script is a written representation of everything that will occur on screen. For example, include camera angles, lighting, props, sets, locations and emotional responses along with lines. You may also want to include some special notes during difficult scenes to give the crew some insight into how the scene should play.
From the script, you can develop the storyboard. Storyboards are visual representations of the actions dictated by a script. These can be helpful for the cinematographer as he lines up shots during production. If your movie is animated, the storyboard is the most important part of production planning. The storyboard must be exactly what you want to show in the movie. You cannot afford to waste time animating scenes that you may not use in the final product.
If your movie is not animated, the storyboard is still essential. However, you have a great deal more flexibility when shooting live actors than clay or models. In fact, each scene should include an alternative storyboard. You may want to incorporate more long shots during a fight scene or try extreme close-ups. Making two separate storyboards can give your crew lines to follow to make the process of shooting multiple angles easier.
Portions of the storyboard should include professional drawings of characters or sets. These drawings can give your costume designer and set builders direction and insight into the words they read on the script. Find a good artist to do these drawings as any details should be well rendered. Simply having a drawing of each character and set can greatly shorten production and photography time.
If you are going to use miniatures or complexly constructed sets, begin construction as soon as you know that they will be. You may be able to shoot simple scenes at first that do not require any construction, but having the models or sets ready before shooting can give your schedule much more flexibility. It can be very stressful to save all of the complicated sets for the end of principal photography.
Another part of construction is meeting with your costume designer to construct any costumes or on-character props (like swords, suits of armor or hats). Your costume designer should have the script and drawings of how the characters should look in order to properly reflect each character with his clothes. Following the construction of a few sets and costumes, you can begin principal photography.