Discuss your marking scale if you use one. A few weeks ahead, ask for sentence-form outlines or annotated reference lists. You can read them quickly and give brief preventive or encouraging comments. You need only about a minute to read and respond to such notes individually, or you can skim through the set and comment in class on the patterns you see. When students visit you, ask them questions like those above.
People can sometimes display real insights into themselves and their topics by stating difficulties.
Then instead of supplying answers, discuss options for proceeding. Encourage students to come up with their own sense of what is possible and most important. Confused writers often profit from being challenged to state in three or four sentences why they have chosen this topic, what they want to say about it, and why that is worth saying. You're not the only one who can give helpful comments on drafts. Call in specialists when needed.