The teacher’s first priority is the teacher’s himself (!).
How about learning a new word for example, per day, unless your language is English – and you are an English language teacher. I'd say the same for other school subjects: we must be updated in some way...
The teacher is the main “resource” for the class. The more he's motivated the better. The more he works for his students, the better too.
So if we are department heads we should take care of the other teachers themselves, as a first premise. He, the department head, should be concerned about his colleagues’ labor. And guide and lead his fellows.
Where to? Toward Excellence: one at labor as teachers and one at our students’ learning. If the teachers work fine, the students will learn and acquire and improve their English, or French, or German, or…
If you aren’t a department head all this advice is suitable to you too: all of us teachers have to learn how to work as a team, taking advantage of other teachers’ positive points.
And if there’s a rookie teacher, even more should you help him, and keep at his disposal. This is what I experienced when I was a young teacher: my colleagues helped me big! There was a nice atmosphere, though I suffered the typical rookie teacher’s problems. / Photo from: manhattan-bridge-from-washington-street www colourbox com. the picture is merely an illustration