Oh let me give you some tips that maybe can help you when you draw them?
The character´s pose tell alot about them and their personality (timid, dominant, serious, extrovert,etc.)
it´s like body language
The character´s clothing it also tells you what´s like their fashion preference unless they count with a uniform or something for example idk xd
So to define a character you just need their posture, clothing, and their facial expressions or usual mood so it complements them
hope its useful u.u