>I am now thinking of definitely having them keep a sketchbook and coming up with some drawing/journaling rituals.
Good ideas. On the first day the good students are excited to find out what they can learn. It is good to give them at least one productive way to become a better artist on the first day. Even though it is tempting to use the whole first session on rules and procedures, have them do some kind of practice with materials for at least a small part of the first session.
Consider a small homework assignment due the second day. Make it something that is useful for the second day even if it is only a written list of visual observations in their environments.
Homework Example: Look for a place in the school building or in your house that has very interesting lines when you see it from a certain place. Sketch it or describe it by answering this this question using 3 to 5 sentences: What kinds of lines and how are they arranged in order to make an evocative arrangement of lines that you can see in the school or in your home? Any visual element could be used.
Establishing creative work habits is much easier if it is done on the first day before apathy or bad habits have a chance. Assume and expect the best. Show pleasure and a word of praise when you get it. Show surprise and keep hoping if you get less. The second and third sessions can be used to review and finish with rules and procedures.