Come up with an idea. There are no boundaries with animation so you can write anything from pigs in outer space to a sponge living at the bottom of the sea.
Pitch a few of your ideas with friends and children. See what they like and what intrigues them the most and, in the end, decide yourself which route you are going to take.
Learn the basic screenwriting format. Purchase a screenwriting program to help you with the basics, but you should also learn tips and tricks of the trade that will help you become a successful writer.
Read other animated television series scripts. Looking at what has sold and is successful is the first step in creating a successful script of your own. It may take several drafts, but rewriting is a huge part of the process.
Begin writing your script. Always start with a “FADE IN” and the location of the scene.
Remember to put “DAY” or “NIGHT” after every location setting. Avoiding using terms like “DAWN” “DUSK” or actual times of the day. Ex: INT. ACME TOOL FACTORY – NIGHT.
Write in a lot of description, but still keep it brisk. Animation is a lot about the visuals, but do not keep it too wordy. If you are purposely writing a visual shot then use cues in all caps like “MOVING TOWARD CAMERA”.
Keep the script to around thirty pages long. Each page represents about a minute of airtime, so a thirty-page script will be the length of a half-hour show.
Do not worry about budget. Anything can happen in animation, so if you want to add an explosion, car chase or anything that would be high budget in real life is perfectly fine.
Keep the scenes one page long if possible. Viewers and readers will get bored if a scene goes on too long, and a key thing in animation is the face-paced action and quick cuts between scenes.
Start and end each scene as late as possible. This is a key rule of thumb for any script and will help keep the story interesting.
Show as much action as you can. Instead of having a character say he is sad, use his actions to show the sadness instead of dialogue.
Try to put as many jokes as possible if you are writing humorous animation. Three to five jokes a page is the average, but by putting six or seven, you are covering enough ground to make sure that there will always be a possible laugh.