Personally, I took just one course. It was mixed with Kufi and Ruqa'a. We started with Kufi (ruler, compass, rotring thin pen), and practiced some few times, then with Ruqa'a. I found it easy,
Good points.
* Sitting well is the most important thing to learn to prevent back and neck pain.
* Learn how to take care of your materials and nibs to save them and keep them for a long time. They are very rare and expensive. Clean nibs after work to prevent clogging.