Reward and punishment is a very simple conditioning theory. A habit rewarded with pleasure will be strengthened and therefore internalized. However, a habit punished with pain will be weakened and eventually eliminated.
To practice this theory is easy. Once you accomplished a short term goal (i.e. passing exam, studied for four hours, handed your assignment etc), please reward yourself with something pleasurable. After you have done this several times, your positive habits will be strengthened and you will eventually adopt and internalized the habits subconsciously.
Similarly, punish yourself with something painful for any indiscipline. I do not mean for you to punish your conventional failure, because failure can be very subjective, depending on the prevailing circumstances. For example, failing in a test not necessarily means a letdown. If everybody else fails, it could mean the questions are beyond what is expected or it could mean insufficient times was allocated for the test. But if you failed because you neglected your study, the negligence is the indiscipline which ought to be punished.
The punishment has to painful enough and it has to be closely associated with the indiscipline act. This to ensure you will consciously and subconsciously avoid the behavior next time. This is a simple scientific fact. Human mind and body is conditioned this way, i.e. to avoid painful experiences and repeat pleasurable experiences.
Your reward can be playing, spending time at the beach, going for a movie with friends, party with friends etc. As for me, I enjoyed every moment I could. I studied hard but at the same time knew how to have fun. I would always seek pleasurable activities only after I think I deserve to enjoy it. I would always associate my enjoyment with my achievement.
For instance, after completing two hours of study, I may go to watch my favourite sitcom Friends or cartoon The Simpson. Another example is after spending the whole Saturday revising study materials, that night I might spent with friends at movies or at some coffee house. So subconsciously my mind and body were recognizing that my pleasure was gained only after putting a lot of effort into something worthwhile.
Next time when I wanted to sit and do some works, my mind and body automatically geared into pleasure seeking benefit. This in turn will empower me to accomplish as much as possible so that the pleasurable experiences ahead can be enjoyed without guilt. Once this became a habit, working and studying become almost effortless, because the mind is set on the on-coming pleasure.
Similarly, the punishment has to be painful and harsh enough for you to suffer from it. The punishment could be missing your favourite program on TV, missing your favourite food for a week, missing a meal for that day (or better still, starve yourself for the whole day), sleeping without blanket or walking in the middle of night in windy winter for half an hour.
To be continued ...