Here’s the thing about habits and rituals: They are enormously evolutionarily advantageous. We are cognitive misers; making decisions and remembering things take energy (which is finite), and forgetting things can be very costly–even deadly. So, we’re primed to form habits, because they offload this effort. The productivity books and blogs are full of anecdotes about Famous Admirable People establishing rituals to free up their headspace (e.g., Einstein had a closet full of clothes that all matched and never wore socks; he could just dress at random without putting effort into choosing garments).
Any task that you can initiate in under two seconds is not perceived as requiring effort; it easily slips into habit and automation: Putting on a seat belt, switching off a light, grabbing some M&Ms from a bowl on someone’s desk, glancing at a cellphone.
As this little list makes obvious, there are up and downsides to this mechanism, as an unhealthy or downright dangerous habit can form and ossify just as easily as a good one.
So, I love that this guy’s nail-polish hack–by creating a consistent distraction–effectively increases the cognitive effort of the habit up beyond the threshold, so the automation falls. Maintain this consistent cognitive load, and the habit softens up and becomes far more susceptible to modification.
 Check out the bit on the “Dual Process Model” here, and consider some of the research that went into Google Glass design–I mean, the functional design, not the awful aesthetic or complete lack of ethical consideration.
 I have to work on fiction early in the morning, before my kids wake up. 5:30am is a *terrible* time to have to expend *any* cognitive energy on decision-making and follow through, so I absolutely minimize decisions that need to be made: I leave my pad, draft, or computer on the kitchen table, next to my cellphone (which is my alarm clock). Alarm goes off, I go to the kitchen to turn it off, and the work is right there.