I
think this question is related to “Where do you get your ideas?”

Seriously
when Haidyn from Dark Secrets turned up in his lovely red coat and said he was
a whore I just went, na-ah I can’t write that. Needless to say he stuck around
until I did.

I
guess I see and hear the characters in my mind, but most of the story is
impressions that I give voice to, sometimes it like watching a film without
sound—some scenes are so clear there is sound.
Other
times I'm running around in the dark wondering who turned out the light and where
is this story going, only to pop out on the other side with total understanding
and a new appreciation for the hell I put my characters through (it’s for their
own good, really, and not one has complained yet).
Once
their story is written that is it, they leave me in peace and new people populate
my mind.
I'm pretty sure non writers don't get it. When I get asked what I'm thinking about there's a dozen different things going on, like the heroine's backstory, how does the magic in this world work? Is the hero good at sport? Should I have another piece of chocolate? The heroine seems a little lost...is this about her self discovery? That is a very cool scar Mr. Hero, how did you get that? Oooh *shiny new hero walks past and flashes a grin* who are you? He brought wine! Plotting party in my head! I should totally have another piece of chocolate.
Where was I...I listen to my characters and they tell me stuff, yes I know it's my subconscious but it's kind of cool that all of that is in there just waiting to come out.