Firstly, I would say instead of serious preparation, you should do sincere preparation.
There can be no such perfect time table/schedule which one can follow thoroughly for long time. But it would be better if
- You give as much time as possible for it.
- You always study in a good mood.
- You study early morning (not acceptable in all cases).
- After your classes, first of all you should make a schedule about which work to be done when and what time should be given for it.
- You always tries to achieve those small goals instead of thinking big.