If there's one major difference between myself as an instructor now and when I first started out (there are, in fact, several), it's that I have become increasingly good at staying out of interesting classroom discussions as they are happening.
Class yesterday was Book I of the Republic, which is one of those texts that will be immediately engaging to anyone with the slightest interest in political theory. It also has a lot going on in the text, so there are a number of different ways the discussion can go. I'm having the students sign up to begin class once over the course of the term, and the student who did so yesterday started with one of the broadest possible questions: which of the three theories of justice presented is best? And... they wanted to talk about it. So I let them, for about 40 minutes out of 80, before making sure we covered everything and not just what they wanted to talk about. I would interject occasionally to add a clarification or re-direct a comment, but that was pretty much it; they were discussing the important substantive issues, but in their own particular way. At 40 minutes, I blew their minds by suggesting they were not necessarily supposed to agree with Socrates (one student literally said something like "oh s***" when I said that).
That's something that would never have occurred to me as a grad student: texts, back then, were dense webs of ideas and associations which it was very important to get just right, and, consequently, discussions had to be keyed on forcing students to recognize these distinctions. This goes over poorly in introductory classes, because the last thing students who already doubt the utility of political theory want is to be told that it's too complicated for them to understand. Now I want them, especially at the beginning, to understand that there's something at stake in all these questions, and that they can be interesting and strange and (sometimes) thrilling to argue about. But, rather than determining what they will find interesting (of which at 30 I have, at best, a slight idea; so much the worse for me when I'm older), I'd rather have them lead me to it. One good discussion at the beginning will buy a lot of goodwill in the future when things might be more difficult. (Aquinas, I'm looking at you.)