I use Scratch less and less at the high school level as it becomes more and more used at the lower grades. None the less, I still teach Scratch for 3ish classes in my introductory course as it is a great introduction into computational thinking. The additional activities that I used to do may be valuable to some teachers so I will attempt to curate them here.
For Complete Scratch Lesson Plans: Go to the Lesson Plans Tab... Computer Science 10
For Example files: Go to DropBox. Includes teaching examples and completed student projects.