The secret to creating a good class is to develop it “backwards.” What the student sees first is the PowerPoint slides, then the instructions for the lab, and then the lab itself. Put most of your effort into creating the lab exercise along with an automated script that runs the whole lab. After you have that, insert comments into the script explaining why each operation (step or series of steps) is being performed. At that point, it is possible to translate the lab into a workbook format. Only after the lab and the workbook are done should you create the PowerPoint foils for presentation, based on the lab and workbook. By working “backwards” in this fashion, the class will appear seamless when presented “forwards” (presentation, workbook, example). It all seems to naturally flow together when the student sees it.