By trial and error you are able to refine and enhance your online course. But why not seek input from students throughout the process, not just at the end of the course? Students can thus help you to improve your course, perhaps even to make some adjustments before the course ends.
For example, you can conduct surveys on activities that are most appreciated, or you can ask for their suggestions for improving the course.
Even if it makes course design more time consuming, you might find it useful to make collaborative sub-group assignments so that students create content collaboratively.
Depending on the kind of course, these assignments can even be used with the next cohort. In addition, the first student cohort might help to identify questions most often asked in the context of a distance course so as to create a FAQ page for subsequent groups.