I am completing a Ph. I look forward to hearing from you.
It is unlikely that a teaching-only ad will be asking for sophisticated small seminars; chances are, you are being hired to teach the large intro courses, surveys, methods courses, and so on but judge each ad on its own merits.
The cover letter should be used to outline your academic accomplishments and to share a five year vision for where you are heading into the future. I have had students spend a fair amount of time in smaller groups in which they not only talk and think together, but write together, particularly in literature and writing-based courses for which I was a teaching assistant.
The fact is, very few tenure track jobs outside of community colleges actually need a teaching-centric letter, and this is a point of great confusion among job seekers.
I am a proven and creative classroom leader, and have served as a teaching assistant TA in a number of courses in the UC-Davis Department of Theater and Dance, a department known amongst students for its rigor. Understand the different missions of the institutions for which you are applying.
Adapted from a template provided by Robert P. I will gladly provide any other supporting materials upon request. OR: I am finishing the first year of my postdoc with XX [your PI's name or in the lab of XX], where I am working on X, Y, and Z [briefly describe, but leave the bulk of the research description for the below sections].