Can the people who interview well, what is the overall high0-level algorithm?
Let me attempt one, Cunningham's Law's style:
* study the WIIFM of the interviewer (IF HR, then.. CEO.... COO.. Hiring Manager... peer...)
* create rapport
* eye contact (look at the top of their nose, center of the eyes)
* listen, really listen
* active listening (this is a bit controversial, some people believe is damaging)
* use "I" when talking about accomplishments and "we" when talking about teamwork
Anything else?
In engineering interviews especially I don’t penalize people for being nervous, anxious, not having perfect social skills and so on. However, it does get old to see candidates who are trying to flatter their way through interviews or who think they can simply game their way past the questions.
Which might also answer your question (though it's not a reliable algorithm!)