How Do You Write Action?

"I watch what I write on a screen, a big screen in my head. So when I'm writing action, I'm watching the action and then I'm writing it down from what I see" "The script morphed and changed as Ed came in as a director," he said of his new co-star Edward Norton. 'You need detail and action, but at the same time, not so overwhelming that a reader can't get through it'