Enthusiasm

Personally, I have always found that my level of interest in and attention to a subject is directly proportional to the teacher's enthusiasm.  To me this seems logical.  If a teacher is passionate and enthusiastic about the subject he/she is teaching, then the student has a reason to be excited also.  Similarly, if the teacher can't be bothered to take an interest in what he/she is teaching, why should the student?
Throughout my educational experience people have asked the eternally boring question: What is your favorite subject in school? The answer can go one of two ways: (1) whichever subject in which the student feels most capable; or (2) whichever subject is taught by the coolest teacher.  I always picked number two.  In seventh grade my favorite subject was English, in eighth grade - Math, in ninth - French.  It changed and was almost entirely dependent on who the teacher was and how much they enjoyed their subject. 
The best example of this was my seventh grade English teacher who absolutely loved Shakespeare.  We spent a great deal of time in class discussing Shakespeare, learning about his life, and reading his plays and poems.  In most situations this would have seemed a major overkill but because the teacher was so committed and sincere in her teaching, it seemed perfectly natural. 
While passion and enthusiasm are clearly an important part of teaching, it is also important that the passion be in the subject area of the class. I once had a history teacher who was incredibly passionate... about Lunchables.  She was convinced that they were the spawn of Satan and that all the children would rot in hell forever for eating Lunchables on a regular basis.  Most of the kids in that class couldn't tell you when the Magna Carta was signed (which by the way was 1215 [lunchtime!]) but we sure learned a lot about processed meat.
Go Lunchables!

Authenticity

Authenticity is one of the most important aspects of teaching.  It is the gateway to honesty and fairness, and provides the basis for a good classroom environment.  In my opinion there are no limits to expressing authenticity.  To be authentic is simply to be what you say you are.  If you say you are a fair person and you intend to treat everyone fairly and you do so, then you are authentic.  Authenticity should not be confused with being an open book.  Being authentic does not mean that you must share every real thought and feeling you have every time you think or feel it; those things require censorship.  To be authentic you only need to be true to yourself, unless your true personality is mean, judgmental and generally negative.  In that case, being fake is the best shot you have at teaching anyone anything. So for argument's sake, let's assume you're a nice person.
A lack or loss of authenticity in the classroom can have an incredibly detrimental effect on students and their learning.  A student can always tell when a teacher is being "fake"; its instinctual. Once a student has detected that a teacher isn't being authentic, that student will most likely lose respect for the teacher. When this happens, it becomes more difficult for the teacher to do his/her job and the students will learn less than they did before and the classroom environment becomes more negative.
In general, if you feel the need to put on airs in order to be successful at your job, maybe you're in the wrong field.  Some people are better suited to office work than to teaching or better suited to a laboratory than an auto shop.  Whatever the employment we should always be true to ourselves, that way we have a shot at being happy. If you hate your job on a good day, you're doing the wrong thing. 

Compassion

When I was in second grade, my class had a show and tell day where everyone was to bring a special stuffed animal, toy, or pet to share.  Everyone was thrilled to have the opportunity to share an item; it was the talk of the town (in the second grade classroom anyway).  The day finally came and everyone brought their favorite toy or trinket to school -- everyone except Natalie.  My poor friend Natalie had been running late for school that morning and in the chaos of trying to get to school on time, she forgot her stuffed bunny.  She was devastated.  Luckily for her our teacher, Tina, was an extremely compassionate person and she wanted to make sure that Natalie was able to participate in the show and tell.  The school had already attempted to phone Natalie's parents but they were at work so it was up to Tina to ensure that Natalie felt included in the day's activities.  She told Natalie to take her pick of the classroom toys and share one of them but Natalie said that it wasn't hers so she couldn't share it.  Some of the kids in the class offered her their toys to share but the response was the same.  It seemed a lost cause but Tina had one more idea.
Come lunchtime, the class was excused to the courtyard and the teachers to their lounge.  Tina, however, got in her car and drove to the nearest toy store where she purchased and brand new, pink bunny.  She came back to school and called Natalie into the classroom.
"I found this at lunch and I think it's in need of a home," Tina began.  "Do you think you'd be able to take care of her? I'm sure she'd love to participate in show and tell."
Natalie was ecstatic.  She thanked Tina a hundred times over and was the first to share when the rest of the class came in from lunch.
Some would classify this act as unnecessary, an overkill, but to a seven-year-old girl an overkill can be just the right thing.  There's nothing to say that Natalie wouldn't have survived without a toy.  Most likely she would have been upset for a time but come Monday she would have been herself again. We can never truly know how deeply a negative experience will affect a child so when in doubt, I believe it best to err on the positive side -- even if it is "unnecessary".

Respect

We've all heard our parents tell us to 'respect our elders'.  We've all had teachers tell us to 'respect our peers/classmates'.  But what about teachers respecting students?  Though we may talk about this idea in a collegiate setting, I have been present on too many occasions in a classroom where it lays dormant and forgotten.
Respect is simply to show due consideration for others, their opinions, and their beliefs.  This is of particular value when working in a choral setting where some believe (and I tend to agree) that the sound and focus of a group is directly dependent on its social dynamics.  This being the case, respect is of the utmost importance.  Students should respect one another and the teacher.  How do we achieve this? The easiest way is for the teacher to first show respect to her students. 
If a teacher storms into a classroom like a bat out of hell and condescends to her students, you can bet your bottom dollar they aren't going to respect her.  If, however, she enters with authority and a general respect for her students, the students will feel worth while and will return the respect they were given.  It all boils down to the Golden Rule, "Do unto others... " etc.  If the teacher fails to respect the students (as she wants to be respected), the students will lose respect for the teacher, and the teacher will lose control of the classroom.  This, of course, means that the level of learning and productivity significantly decreases. 
In essence, respect is one of the basic pillars on which the order of a classroom stands.  Without it there is division and chaos; with it comes the opportunity to create a learning environment that is rich in equality, diversity, and a general presence of positive energy.