Of all the categories of voice acting, none are as potentially intimidating as how to become a voice actor for cartoons.
Character work offers a lot of challenges. You must be a great imitator and be able to fantasize your self in different comic situations. You must be a great “pretender.” You must also understand pitch and timbre much more in-depth than on other kinds of voice over work.
It is very important to create your own experience and find the time to do it, particularly if you’re young and haven’t experienced a lifetime of human interaction and observation of human beings and their peculiarities and foibles. One of the ways to get a concentration of experience in these areas is to immerse yourself in several areas of voice over that will contribute to your learning how to be a cartoon voice actor.
Practice commercial scripts that go to extremes in delivering the message, especially those that use character voices. Practice on animation scripts that will help you develop your feel for specific characters. Many scripts that are generally readily available for practice are video game scripts, which have a wide range of characters, all the way from friendly to macabre characterizations. In addition, get used to working with long narration scripts that require patience and endurance, as well as character identification. Children’s audiobooks are especially useful for this. Work with your voice over coach on all these sources.
As I have said so many times. It is crucial that you look to the meaning of every script. Just reading it aloud will get you nowhere. What is the script about? Who am I? Who is the person I am talking to? Where am I? What am I seeing? Experiencing? See everything in your mind. Get a real bead on the characters in the script. Am I happy? Content? Uneasy? Angry? Meek? Aggressive? Know-it-all? Braggart? Nagging? Sarcastic? Am I good-looking? Skinny? Overweight? Theatrical? Tall? Short? Do this also for the person or persons you’re talking to.
Use your creativity and imagination. Make it all real. Do this as often as you can. Get in the habit of making this your number one goal. You’ll be amazed at the results over time.
When you get to the point of auditioning for the work out there, keep track of the kinds of characters you audition for that end up with positive responses. These are the ones you need to focus on, the ones that will get you work.
Animation is very popular, and there is a lot of work out there. Practice. Audition. Persist. Wash. Rinse. Repeat.