A lot of what's been described here is how I like to create my characters too. I think it's thoroughly important to think of them not so much as fictional characters, but as people. I mean, how do people function in the real world? Well, one thing for certain is that not everyone is going to like the same person. So why, in any circumstance (parodies excepted), would it be appropriate for a character I or anyone else makes to be liked and tolerated by all other characters? The creation of a Mary-Sue is clearly specific to people who do not think everything properly through, or who are new to creating fiction.

Similarly to what has been said, I can draw inspiration from nearly anywhere and everywhere, although some places more than others. I do like to observe people in public and wonder about their lives. It's very interesting, and it's also why I think psychology is useful in the circumstance of creating characters. The more about humans you can understand, the better you're going to be able to create ones of your own (or other species with humanistic traits).

It's been ages since I created any new characters though! I need to get back into writing.