1. Set out a rota as to when your going to study what. It can also help to make a list at what you need to study more and what you don't so that you can improve on them.
2. If making a rota isn't your thing or it doesn't work for you then simply planning what you will that day can help you get into that mindset of doing work. Then, at the end of the day, right down names of topics you revised or even what you can remember about them topics to help keep it in your brain.
3. Find out what helps you to remember most, perhaps just reading, taking notes, seeing something visually, talking aloud. A good website to use is Anki , you create flashcards, then when you go through them you have to say the answer to yourself, speaking out loud is said to be an effective way of learning, then click to see the answer. There is a more effective version which you download to your computer here
4. The brain usually can focus completely for about 20 minutes, however if your in a mood to be able to get on with work then work until you loose your focus, but try not to make it much more than over 40 minutes. Have a quick 5-10 minute break every 20 minutes to help re-fresh and re-focus your brain. Good activities can be going for a walk, doing a bit of exercise (skipping has been recommended to me and is also a good sport to keep healthy), drawing, or whatever can relax you that you don't need to put a lot of work into.
5. Make sure you get quite a bit of sleep, sleeping helps your brain to make connections with what you need to know. Depending on your age it can vary but it should be no less than around 6 hours, more ideally 7 or 8 hours should be what your getting. If you find it hard to sleep, try to seek out the problem through whatever way you need to. Don't suddenly decide to go to bed 2 hours before you normally do, make it gradual, start with maybe 15 minutes or so then slowly increase it.
I hope these help^^
- Zin x