I think mushin or no mindedness is an often misconceived notion. It's not something you can just switch on, most just stand there like the lights are on but nobody's home. That state of awareness or mindfulness (if you want to get all jedi about it) comes naturally when all the other components are in place.
For the mindset I often liken to an explosive. Most people walk round with some very unstable explosives in their heads. It often goes off at the wrong time or sometimes fails to go off at all. Intent is the explosive behind our moves. I try at get my explosive stock pile as stable and large as possible. Anger, fear and other emotions and jumbled thoughts is like storing your bombs in a cold, damp, hot or whatever sort of conditioned room. Using that analogy have you ever noticed how angry people blow their load (pun intended) really quickly?
I try to store my stockpile in a nice cool, calm, large room. When something starts me off its like lighting a fuse that sets off a very large chain reaction that keeps going.
I work as a Doorman and once you get this chain reaction set off you really have to mentally stamp on the fuse like mad to put it out. The way a lot of people talk about no mindedness reminds of them setting up a lovely cool storage room, but forgetting to load it up to the brim with explosive.