Dave,
Have a back up activity of some type to use when you need to catch your thoughts. I have a number of case studies that I bring to class and can hand out when I need to get my students to thinking and problem solving. The case studies can range from easy to more difficult this way you will have them available no matter where you are in the course-beginning, middle or end. Also, I have questions listed that I can use to start class discussions.
You will be ready to go again once you have worked through one… >>>