If you want my opinion on my OC's, ask and you shall receive.
I don't know if this is the case for most people, but I tend to create my characters from the various emotions that I feel throughout the day. Take for example my OC's from my series, Guild of the Maltese falcon.
Rebecca is a bit on the ditzy side. (What with her being blonde.) But it's more or less trying to understand herself and the world around her. Call it self-discovery if you like. That's my current state at this point, especially when I need to live my own life.
Elizabeth represents what I feel whenever someone or something is really getting on my nerves. Just makes me want to break out and fight someone. It's that feeling of wanting to strike back at those that did me wrong over the years. (With some borderline sociopathic tendencies.)
Andre is the what I strive to be. Someone level-headed and collective. Also someone that knows something about everything. But most of the time, nobody seams to notice.
Jessica is what I used to be as a kid, quite, content with the rules set in place, always trying to not get into trouble. But sometimes trouble just pops out of nowhere for her. (Considering the predicament she's in.)
Even though I made them out of emotions, I tend to not let them become a cookie board cut out of their emotions. I try to make them out to be people that you would tend to run across in your everyday life.
So, that's my take on the matter at hand.