I've noticed that the homework sets and the exams are over the same basic concepts but do not have any other similarities. Perhaps it would make the homework more meaningful for the students if the homework were similar to the exams or vice versa. One approach is that lectures and homeworks are there to help you pass exams. That will get you a degree and you may want to use this approach in some courses as a survival mechanism. Really the lectures are supposed to explain a subject, homeworks help you know whether you have understood it and exams are just there to check that you really did the work.
Exams have to be short, easy questions if they are to be done in an hour of panic.
Homeworks are supposed to make you think and search for information. If it was obvious which equation to use and how, a trained monkey could do them. On the other hand, they should not waste time in useless hunts. Given all that, any suggestions for improvement would be welcome.