An author can develop characters in how many different ways?

There are many ways. The author can start with the character's physical personality and then define his thinking. Or the author can build a mind-set for a character and accordingly state its physical appearance. Or by giving a definite past for a character also draws its present. Or by stating its profession or any personal factor gives a base for character building. And also the author can use personal experiences or real life people while drawing a character. And many more.