Research
It can be helpful to try to figure out why certain characters and their characteristics work, but some of them are not working as those good ones. There is no shortcut or easy way to design a character. Stereotype sometimes works fine, but it might be boring too.
It is always good to look at reference from commercial TV or video game. From analysing existing character that the styles, background, or even appearance is close to your character, it might give you an idea that what kind of characteristic helps you to develop your character.
Aiming
What are your audience? And what kind of people will like your character? It is always helping to think your target audience first before you start a design. Is your character in a kid show? Or is it for a action show that mostly view by adult? Usually the characters for children show use brighter colour in their design. As to adult show, people would like to see complex details on their characters.
Accessories
Does your character fight? Or is your character rich? Accessories not only give out the personality but also background information for the character. Sometimes accessories have real function in the scene. For a time traveler, they might carry their time travel machine with them. It could be a watch. Whenever they travel across time, the camera could have a close shot on the watch.
A character who likes to sleep could hug a pillow all the time. That pillow becomes personality accessories. It definitely tells the audience something.















