Firstly it should be clear that quantity of studying is not the guarantee to fetch you the marks or grades but it is the Quality of Study which definitely can.
Secondly the VU has a different way of imparting education. It does not requires you reproduce all what is taught to you. Means does not requires cramming.
Thirdly here in VU there is no chance of relying on guess or leaving some thing as less important. Therefore you have to go through the whole 45 lectures. So you are required to remember each subjects thoroughly. Another important thing is that VU relies more on concepts than bookish language/cramming.
Fourthly marks other than Mid & Final Term papers are very much important which includes the assignments, quizzes and GDBs. Leaving anyone of them will bring your grades down. One very interesting fact about these is that they help you a lot in improving your grade because these are announced well before time and mostly requires a little effort. So just do not take them light.
Now a recommended way of studying especially for those who are doing jobs and have less time. It is pertinent to full time students as well if they can follow this guideline:-
Get all the handouts and the lecture DVDs.
Visit LMS daily to see any forth coming activity and make program accordingly.