After my first semester, for every class I have taught I have created an independent course website holding the syllabus, weekly blogging assignments, links to readings, assignment descriptions, and an embedded Google Drive for draft sharing.
While respecting FERPA guidelines, I still use Google Drive as the primary means of responding to student writing. My students use Google Drive to comment on each other's writing during peer review sessions, and I give all in text feedback through that platform. However, each student does receive an individual print rubric with an end note and their in-progress grade. I've linked an example of my in-text feedback to student writing saved as Microsoft Word document files here, shared with the student's permission. [Research Paper with Instructor Feedback]
In my teaching experience thus far, I've communicated with my classes over email. I employ a casual tone to engage with my students over the informal medium. In the future, I anticipate using the Canvas course management system to communicate with students and provide feedback. In my experience with Canvas, it has been vastly more user-friendly and flexible than the Blackboard course management system that was used for a time at my previous institution.