First of all, you should set a realistic goal for yourself which will motivate you to work hard. Consume more time in studying your courses which will help you in achieving your target in an effective manner.
Make commitment to yourself that you will consume a certain number of hours in studies and also set short term targets like getting maximum marks in mid-term etc.
You should avoid all bad habits like having alcohol and smoking. Also reduce time of hanging around with friends. It will help you in spending more time your academics which will bring you desired results.
Make a time table for the day and remain stick around it. Do not miss anything that you have included in your schedule for today.
With commitment and consistency, there will not be any hurdle left in your way that could stop you from becoming an outstanding student.
Attend all classes and also make interaction with your teachers which will help in developing a better understanding of all subjects.
Do not miss any test in your class as it will help you to judge your preparation in that particular subject and will also assist you making required improvement.