Vicki writes (and gave me a smile in the process):

I think teachers who waste time at the beginning of class don’t take their job seriously. (I say start quickly, get it done, and then enjoy the teachable moments at the end of class. But if you’re stressing about getting your objectives done at the end of the class, you miss the valuable time at the end when you really have breakthroughs with your students.)

This is a great line that, I believe, can apply to more than just our classrooms. Hit it hard, hit it fast. Focus on the content and the discipline becomes a non-issue. Focus on quality teaching and engagement will follow. Just start quickly.