The first is regular study, during which the efficiency will be higher. This is certified by experts. You can't study hard, and your brain needs rest. If you study and rest regularly, you will get twice the result with half the effort.
Then read more books. Some people like reading books, while others prefer watching videos. Some people like to study with friends, others like to bury themselves in books and study quietly, so they may relax their studies better in books.
Finally, you can turn off your mobile phone, uninstall mobile games, and you can't be distracted, but you still have to get enough sleep. Only when you have a good rest can your brain work better.