For me, the story lives inside my head. I imagine everything almost as if it were being filmed. Sometimes there'll be starts and stops as I jump around in my head, imagining one scenario then wiping it away and zooming the characters into a different action. This is especially true of action scenes - I imagine them going down in a very cinematic sense - leaps, flying kicks, punches. I imagine the rooms where the fights occurring and what could become a weapon or an obstacle in the fight.
I play music and just let my mind get carried away in imagining the scenes in action. The voices don't really come alive until I'm actually writing, though there'll be some words that are so important that they are born in this phase of dreaming up the story.
I think this period of dreaming the story is where I get to experience the entertainment factor of the story - feeling the emotions, imagining the action. It's less about finding the perfect words or turn of phrase, but merely letting the characters loose inside my imagination and enjoying the ride.
One of my favorite parts of Buffy the Vampire Slayer is that Buffy is the girl who kicks ass. She's got the moves. And I love writing that. The action scenes. More than that, I love imagining new ways she can move and attack to keep it fresh and exciting. So yeah, action has been on my mind a lot. Guess that shows where my writing is headed again.