Former Disney animator Charlie Bonifacio in offering his thoughts on designing animation characters encourages originality motivated by a sense of story.  Charlie sees personality contributing to a  "more satisfying" character design.
In my observation, the wisdom of the day is to find a snappy graphic style that sells.  Maybe even steal it from someone who's successful.  In my experience, character design comes out of a story and from what the character does within that story.  Essentially who they are.  I arrive at designs by exploring personality, actions and mannerisms through an initial form concept.  Then try to find an appropriate design that emerges as the personality of the character emerges.  This process may take longer but it's ultimately more satisfying.  Look at designs today, snappy looking but so often devoid of real personality. 
Charlie Bonifacio     Character Design Contest Rules