Strong Ending

You want to preserve the impact of a lesson. I've seen some great lessons get smothered because at the end of the lesson came the class announcements, the lead-in for next week, and miscellaneous stuff. The burning impact fizzles out -- all the oxygen just got sucked out of the room and people are distracted.

Put announcements up front; they'll be less distracting to the lesson.

It's good to give a "preview" of the next lesson to build anticipation. But sometimes you have to say too much, and it will detract from the zing of the current lesson.

So here's one strategy you might try: "Watch for my email by that tells you what to expect next time, and what you should do in advance."

Simple, easy. Build anticipation for the message, but don't give the message itself.