I tend to need everything planned out. That way you can insert stuff early on that nobody will really get until they finish the story and maybe go back, reread, and understand this vague reference or hint.
I like it when shows/anime do it. You'll maybe see something or hear something mentioned in the first episode but you'll have no understanding of it until it becomes a main plot point twenty episodes later. It's the little things like that that tickle my fancy. It's probably why I like reading Stephen King. He puts a lot of little things like that into his stories.
“Power in the hands of the reformer is no less potentially corrupting than in the hands of the oppressor.”