When I taught an electrical engineering class, the prof with whom I shared a syllabus and exams, made the exam problems look a lot like the homework problems. The kids who (probably) cheated on their homework lessons paid for it on the exams.
Perhaps likewise for the humanities courses. In my own experience, writing essays and term papers for the regular course assignments was what got me so I could write a decent essay quickly during a "blue book" exam. I don't know any way other than sheer physical practice, to learn how to do that. You can't pay someone else to practice for you.