Ten simple steps to your next favorite family film!
2. Choose your setting. Maybe your tale is set in a specific time period and/or place, like The Princess and the Frog. Maybe it's just a vague story involving forests and castles and royalty, like Tangled. Maybe it's in-between - showing elements of a certain culture but not too detailed or specific, like Beauty and the Beast (a French tale). Whatever the case, choose now when and where your story will take place and how specific you'll get when it comes to food, clothing, furniture, hairstyles, cultural norms, architecture, etc. Do a little bit of research now, to get an idea of the culture you've chosen and to help with outlines and character sketches.
3. Sketch an outline. First make an outline - nothing elaborate, just numbered steps of the story - of the fairy tale you chose. Then change characters or plot points and tweak anything less than unbelievable or non-kid-friendly. Just make sure the story involves love and some way for the girl to become a princess by the end if she's not one (i.e, marrying a prince, discovering long-lost family, etc.) If the story you chose has no main girl, either add one or make a girl already in the tale center stage. Don't be afraid of changes; the fairy tale is just a starting point! After all, the original The Little Mermaid ends with the prince marrying someone else, so the mermaid dies and becomes a spirit of the air. Not to mention that the princess the prince ends up with, on whom Disney based the seductive-princess version of Ursula, was in the original tale already engaged to the prince before the mermaid met him.
4. Create your princess. (Who, of course, may or may not be an actual princess when your story opens.) Give her a name, a few key traits (not necessarily all good), at least a basic life story and family background, and a visual description. Example: Snow White is a hazel-eyed, kind, animal-loving but naive orphan princess who longs for love. She strives to treat the people the way she longs to be treated, thus winning over everyone she meets except her only relative, her stepmother. She lives in the castle with her stepmother the queen, who envies Snow's raven black hair, milky white skin, and blood red lips.
5. Create your villain. Pretty much the same steps for the princess, plus a main motive to hate/work against the princess, her family, and/or her man. Example: The Evil Queen is a pale-skinned, green-eyed young widowed queen never seen without her crown who longs for the admiration of others. She grows to hate her prettier, more famous stepdaughter - who was always loved more by the late king and the people than the queen was - and turns to dark magic to rid herself of Snow and fill the voids in her life with the admiration of her beauty sure to follow Snow's demise.
6. Create your hero. A prince, a hobo, a thief, an explorer, the son of a baker or merchant - whatever you want. Again with the name, traits, back story, and description. Example: Prince Ferdinand is a brunette royal from a far country who met Snow White once before her stepmother turned on her and she vanished. Longing to be with the girl whose simple desire for love in her life matched his own, he sets out in hopes of finding her alive and willing to return to his country as his future queen.
7. Fill in the side characters. Now give description, names, and some details to the lesser characters - the villain's ailing mother, the princess's bratty sisters, the hero's best friend. You know, all the people you included in the main characters' back stories or who play a part in the story. Example: The dwarves are seven brothers who are each named after their foremost trait: Doc, Bashful, Sleepy, Happy, Dopey, Grumpy, and Sneezy. They live the bachelor life together in a cottage in the woods, passing the time by mining for gems in a abandoned nearby mine.
8. Do your research. Now's the time to look more in-depth at all that stuff we discussed in step two. At this point, you'll have to look at your story outline and characters to know what will be important to know. After all, the cultural expectations within Pocahontas's Indian tribe weren't necessarily the same as other Indian tribes of the time period. (Although Pocahontas is generally a bad, bad, bad example of research. Disney really screwed up their history with that one.)
9. Write your script. Everything we've done has led up to this point. (This is also the step where you should name your movie.) Now we're really getting to work! Here are two articles to help you out: How to Write an Animation Script and Write a Script for an Animated Cartoon. For some true Disney inspiration, check out the full, final-draft Toy Story script - or is The Lion King more your style?
10. Animate! First make your storyboard (sketch breakdowns of each scene to give a visual idea of how each scene should look, play out, etc.). Then to the drawing board! I'm not really a drawing type of artist, so I don't have much advice to give you, but maybe do some online research and/or find an artsy friend(s) to help you out.