Many students fail to develop a good study habit because of the very simple reason: they fail to stick to their schedule. The best way to combat those distractions is to be loyal to your schedule for that time. Refrain from creating excuses and you will see that you can manage your time better.
Self-discipline is very important and the easiest way to impose a self-discipline is to stick on the task or activity that you are scheduled to do for a particular period of time. If you happen to have an unexpected activity, just try your best to finish your scheduled task ahead of time. Remember that if you are known to be a person who does things as scheduled; your peers or your colleagues will also respect your time.
Read more about here and learn how to set your priorities and manage your time efficiently.