So far, practing writing in my classes of all levels was to enhance other skills. Occasionally students ask me how to write a letter. That is the limit of writing Bangla beyond homework. But there are exceptions. My colleague, Thibaut Dhubert, Bangla professor in the University of Chicago writes academic articles in scholarly magazines and my former student, Jahnabi Baruah writes Bangla poems.
This following article talks about pedagogy of second language writing which I found useful. I am saving the link for my future use and also for the teachers who are interested in it.