I don’t think I study particularly hard, but I do
Oh, and for math classes, you really have to read the proofs. Don’t be one of those students who skips over them because they have no relevance to the problem sets. Reading the proofs will build up your mathematical maturity, just like lifting weights builds your muscles.      
1. Get 8-9 hours of sleep a night. This allows me to go to class well-rested and do my problem sets with greater efficiency.
2. Always go to class. Even if the lectures are not useful, they serve to structure my day. Having lots of free time creates diminishing returns for me – three hours isn’t too different from four hours, but having one block of three hours and one block of one hour is significantly better.
3. Spend a lot of time working on my problem sets before I ask others for help. I like to think that all my time spent getting nowhere on problem sets gives me a deeper understanding of the material. And I don’t know about you, but I find it way easier to concentrate when there’s no one else in the room.
4. Start my sets the day they come out (at least for the first few weeks!). You’ll probably spend more time on them, but being ahead will boost your morale. Plus you’ll have time to go to office hours and you won’t feel pressured to pull an all-nighter on the last day.
5. For some classes, I read the book before going to lecture. Try and have a schedule for reading the book so you don’t slack off. Also, you won’t have time to read the book for all your classes, so choose wisely.
6. Use the Mac app SelfControl to block Quora, Facebook, and other distractions during the day. I promise I’ll turn it on after this answer!
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http://silicongist.com.ng/2018/06/24/how-do-top-students-study/