“Characters” smell of stereotype and fiction.
If you met a character at a bus stop, you wouldn’t want to have a conversation with him–it would feel as forced as sitcom dialogue–and you’d wonder what was wrong with his face. Humans, on the other hand, have quirks and patterns of behavior that fit within the scope of their humanness. They wouldn’t try to talk to you at a bus stop or they most certainly would; they’d talk to a fence post and have a good time at it. But they’d be real. And given the number of examples we have surrounding us, I wonder why it’s so hard?
Collect people like stamps and try to capture their essence in as few of words as possible. If you read it later and can’t remember who they were, how they made you feel, then you can’t use it, which is too bad. But the pretty people aren’t usually memorable anyways, and the ones carrying Rottweiler puppies or a beard to their knees are so striking as to be astounding. You couldn’t possibly have a motiveless character who wears Undertaker shirts and bounces fat babies on their hip.
Don’t be afraid to borrow and don’t so much as write your characters as find them.
Look for Episode IV (concerning bullet 5.)!