For online Linux courses or MOOC’s I wonder if you can take advantage of screencasting software to make the training more effective and fun.
For training purposes I suggest that there should be projects which include the student making their own screencasts of selected assignments.
With enough guidance like a manuscript which has some blank fields they could fill in. They could create this video screencast and explain some related topics in it.
It doesn’t need to be screencasts. With a simple smartphone and a flexible holder you could start to record selected topics from mathematics, physics and so on. I belive you learn a lot with this method. So why not take your math book and make a collection of videos.