I love learning about the wonderous variety of creative processes. Everyone is different.
Something implied but not articualted in your post are the mental associations that come with using these kinds of tools. I expect that you have many years of history writing in cursive with a pencil and typing on a manual typewriter. Sitting down and working with them probably causes your brain to shift gears into a very creative state of mind.
How do you integrate Scrivener into your workflow?