When you are sitting there as a principal looking at 100 resumes for that position and they all kind of blend together, what are some of the intangible traits a principal or team leader might desire. I'm thinking things like life experience, not being late for work, professionalism, etc. How do you sell those traits in the early, pre-interview stages of the job search process?
The cover letter is the time to show your heart and soul as a teacher and professional, at least in a quick and easy way. A resume that is carefully done and worded will also show those traits as well as possible before the interview. Then, naturally, being 100% professional (including ways you mentioned above) while showing your heart and abilities/knowledge during the interviews...put together with the others, will put your best foot forward.
A teacher at one school told me how the principal literally asked someone to randomly select eight or so names from a huge pile of "good" resumes, and those were who got interviews. Not sure if that's the best method, but the teachers at the school are happy and like the principal, and the principal felt like any of the applicants could potentially be a good fit. So, sometimes luck comes into play. Have a good resume, have a good cover letter, and when called for an interview, be ready to shine.
