Exam readiness is something that should begin MONTHS before any tests are due to occur. Consistent (throughout any course) retrieval and spaced practice should help cement LEARNING and knowledge into long term memory to help free up working memory for optimal exam performance. Procrastinators and last-minute crammers might be able to achieve acceptable performance, but this is not learning!!! It is also not sustainable and risks bad habit acquisition for life...
Good habit development is an often under-valued focus of education and growing up. Optimal performance in many areas of life depend on good preparation, and in a busy life it is difficult to change things around when you need to, so good ongoing habits will mean that you are best positioned to excel. Don't forget to consider the below as part of your development towards doing your very best in exams and getting yourself ready for the 'real world'.
Having a good, consistent sleep routine is increasingly being shown in research to be linked with health, longevity and daily performance and happiness. Leave your phone 30-40 minutes before you plan to sleep, try to have your room dark and cool. A hot bath before bed can help relax muscles and mind. There is much research on optimal time period for sleeping but between 7-10 hours is a good range to work from, see what works for you. When things are going well, routines are established and your sleep is good quality you start to wake up around your alarm time naturally.
In the run up to exams and stressful periods, those which are timed such that you feel ready to go/at your most alert/energetic when the exams are timetabled. For example, if the exam is at 9am, ensure that your routine has you up in enough time to wake up, perhaps do some light exercise (great stress/excess excitement relief), have a good breakfast that fuels you and fills you up but doesn't make you lethargic. Also, routines established before your experience additional external stress will help you cope when that stress comes about.
Get your eating sorted for concentration and feeling fuelled and full of energy to help push you through a busy few weeks of exams. Lots of good balanced food, spread throughout the day such that your normal eating times mean you are not hungry or low energy or in a food coma for timetabled exam times. Fresh pasta, brown rice, fish, chicken, plenty of colourful fruit and vegetables, lentils and pulses are all great for gut health and digestion to ensure that your body has what it needs to perform. But don't forget that there is space here for treats and rewards too, but time these not to impact on your exam time (avoid high sugar foods before exams) or sleep (aim to eat at least two hours before you plan to go to bed).
3. Work timetable
Plan what to cover between now and the final exam, try to allocate time to reviewing everything to refresh it, but also plan in time to work on anything that you feel are your weaknesses (or that are revealed to be so as you assess yourself). For example, 20 minutes on 6 topics throughout the day, but with two 30 minute periods just in case. If you need them on those topics, do further practice. If not, you've earned the rest: meditate, exercise, relax however works for you.
Don't work more hours in the day than you are sleeping at night, the brain processes and organises your daily activity while you sleep so working 18 hours a day and only getting 4 hours sleep is not efficient. And plan for breaks, food, time to socialise, catch up with whatever else makes you happy and productive. To improve adherence to your revision timetable, coordinate breaks and meals with family and friends so that you look forward to these, are motivated to work hard and don't overrun breaks and lose working time.
4. Revision style
The best form of learning at this stage is retrieval. Which means testing your ability to tackle questions across the range of topics. Pick a topic to review - e.g. fractions, binomial expansion, area or whatever you are strudying (it doesn't have to be Maths). Find a question, do it, time it, check it and react to your performance. By which I mean a) if you got it right, in good time etc, move on, b) if you got it wrong can you spot errors before you check answers - incorporate and work on exam technique - or c) can you understand it after checking and then tackle another similar question to prove you've progressed.
Going over questions you've already done is no problem, at this stage repetition, 'mental muscle' memory and familiarity are your friend. By spacing out past paper questions you are exercising your mental retrieval in any case and strengthening your knowledge. (Spacing is the practice of testing yourself on topics immediately after learning, a day, a week, a month and so on after - hopefully you have been doing this throughout the course and at this stage you are regularly checking your recall and comfort with topics and questions across your revision timetable). If you want, you could try questions for different exam boards first before coming back to ones you've done closer to the exams as the final push.
I hope that this helps. And good luck with it all! Remember that tests or exams are FOR YOU, no-one else. You have the power to best control what is within your control and be prepared as much as you can for what is not in your control.