My most productive study sessions occur when I am working in a quiet place, away from strong temptations (food, computer, bed)
Motivation is not reliable because motivation is an emotion, a feeling, that comes and goes. You can wake up motivated just like you can wake up feeling any other emotions. The key is discipline. Think of the bigger picture. Ask yourself, if you study , will you regret it after? Probably not. Will you regret it if you don't study? Highly likely, because there are consequences to that. This outlook can be applied to many areas of life. It was first told to me in regards to exercise and weightloss but now i use it for a wide variety of aspects.