You've already mastered good planning, now how about good preparation? Observing this Rule isn't as immediately noticeable (as with the other Rules), but it does show in your results. How does this apply from a Job Fairy perspective?
There are many ways to interpret this Rule. We've always advised job seekers to schedule their interviews (whenever possible) as early in the morning as they can, or late in the afternoon. This means that you are getting the interview over with as quickly as possible. When you go first thing in the morning, you have been battling rush hour traffic and are probably focused on what you are going to do at work that day, not worrying about the interview.
You don't want to seem "too" interested in the company at which you're interviewing. This could make you come off as desperate; as if they're the only ones who have called you for an interview in months, and you're sprinting after the job with all your strength. It should matter enough that you've looked up major details about the company (e.g. visiting their web site), but not so much that you've drafted them a new marketing plan.
When you interview at the end of the day, you've been dealing with work all day long. You haven't had time to obsess about the job, how it would improve your paycheck, how your name would look with the new title on a business card, or what the commute would be like. You should not care about the job at all until the moment you walk in the door of the office where you're going to interview. The moment the interview is done (when you get into your car in the parking lot; they can watch you from the window as you leave), forget they exist.
Of course, you'll want to get the hiring manager's business card so you can send a thank you note later. Once you get home, sit down first thing and write your thank you note while the details are still fresh. That's in the event you want the job. Pop the letter in your mailbox that evening so that it goes out the next day. If you don't think the position would work for you, then skip the note. (They might offer you a position anyway.)
You should be reading the newspaper (at least the business section) on a daily basis so that you have interests other than your job to discuss. It also helps to play a sport. A lot of managers play golf, run, or bike; you may wish to take any of these up or merely plausibly feign interest. (You can be quite paunchy and still be thought of as proficient at golf.)
Try to have multiple things going on that day (i.e. another interview right after the appointment, a meeting of some professional association, or even a date for lunch or dinner) on which you can focus instead of the interview. Having a busy, jam-packed schedule (or creating one, or the illusion of one!) ensures you conclude the meeting first, you don't linger too long at the interview, and that you don't babble pointlessly; you know you have a lot to do and you're focused on getting things done efficiently and swiftly. This is the kind of employee a company wants.