How do you do cartoon voice overs?

Wow! Where to begin...

Cartoon voice overs are a very specific breed of voice overs that involves acting skill, and a voice with great range.

It takes practice with the right voice coach. The mistake many make is believing that sounding cartoon-ish is enough, but cartoon characters literally have to become a new person/character behind the microphone.

Check out some of the voice demos on Voice123. You will find amazingly professional voice talent there, including those who do voice work for Video Games. See the attached interview. You will get great advice from it.