There is no one single, universally accepted set of guidelines for what makes an ideal teacher. In an article from The New York Times columnist Joe Nocera in 2013, a robust national discussion is taking place at the moment concerning defining the characteristics of an ideal teacher.
The prevailing education model in the United States places great emphasis on success in standardized testing. Alternative approaches include those of Paulo Friere, who advocates a critical pedagogy that has become immensely influential in higher education, and Anna Montessori, who believes that students essentially teach themselves and should be given the ideal resources and environments in which to do so.
Perhaps the best general definition of what makes in ideal teacher comes from William Arthur Ward: "The mediocre teacher tells. The good teacher explains. The superior teacher demonstrates. The great teacher inspires.”