Really encourage your kids to go to office hours, especially before exams. I always knew where students stood on the material, who had done the reading and who had not. But almost 100% of the time students were reluctant to come to office hours before exams/papers because they were not 100% prepared (or 25%). I’d rather know a couple of days before the test that they had not done the reading and have an opportunity to discuss it with them. And it sure is better for them for the professor to see for sure where they stand a day or two before the exam than on the exam, which will factor into their final grade.
Also, it’s good advice for freshmen to arrange tutors during their first weeks at school. They can line up the best tutors, and they can get help and advice before a hole has been dug. It encourages them to do the reading so that they will be prepared for their meeting with the tutor. The tutor can give helpful advice beyond the work at hand.
Tuition, etc. pay for all of this. Such one-on-one interactions are often the best learning opportunities.