I usually get inspired by something to create a character. Either a song, someone I know in real life, random person on the street. This is the spark in a sense.
Then I figure out where I want the character in the story. What does he need to bring to it. I give him some very basic traits based on that.
I give him a background. I use the background to give him a base for the traits I need him to have. I try to give him a realistic background. Based on this, all the other traits my character needs fits into place.
Though sometimes I come up with a character first. Then I create the world that this character lives in. From that I can usually find some sort of conflict in it.
Disclaimer: I write alot in my head. Not good at the getting down on paper yet.