I see this with experienced writers, too: They worry so much about the plot that they lose sight of the characters. They lose sight of why they are telling the story. They don’t let the characters actually speak. Characters will start to dictate the story in sometimes surprising, emotional, and funny ways. If the writers are not open to those surprises, they’re going to strangle the life, spark, or spirit out of their work. […]
Let the characters surprise you. Let them take you somewhere you’re not prepared to go. Even if it means tearing up tracks — who cares? Let the characters make you cry or laugh, or let them scare you.

Brian Michael Bendis, Words For Pictures (via comicquotations)