(Credit: http://www.diva-portal.org/smash/get/diva2:637902/FULLTEXT01.pdf)
http://www.creativebloq.com/character-design/tips-5132643
Create a document (Pages, Photoshop).
Write down the personality and the qualities of your character.
Write down what sort of the shapes and visual style you envisage for your character.
Then collect images of related characters, film stars, animals etc that embody the characteristics you've mention above.
Select ones you feel will help you develop your character's look and personality.
Start with pencil and paper and sketch out different ideas of what your character could potentially look like.