Tips to get A* in A'levels

Do your homeworks regularly and avoid copying from friends. If you do so, you’ll risk your own grades, not the teacher’s! And divide days for each subject, and try doing what has been done in it since you last revised that. On weekends, you can do two subjects per day (or even more if you can), and review all what was done throughout the week. 

Once you’re done with the full chapter, try solving questions from the past papers. After trying them yourself, refer mark schemes and examiner reports. Furthermore, make short notes, chapter-wise, based on the past paper questions. I’d show you a few I made (though, due to shortage of time, I couldn’t do much). This really helps a lot for last-minute revision. In these short notes, you may even add those points which you think you might forget.For maths, regular practice is needed. As for me, after the chapter has been explained, I’d do all the questions in the past papers from that chapter. Again, for this do it yourself, rather than looking up the mark schemes. Solve question from other sources. That helped me a lot. Once I was done with all the chapters, I solved all the papers yearly. 

Tips For  Mcqs
start solving chem mcq paper from the last question and go back wards....
start from Q:40 and go backwards till Q:1
i used to run out of time when solving the paper, and i tried doing this and coudnt believe i was able to complete the paper in about 40 minutes
--leave the calculation questions and do them after finishing the rest...it'll save time.. 
for section B If you are 100% sure that 1 is wrong just mark the answer C
and if you are 100% sure that 2 is wrong , just mark the answer D
If in the end you have time , you can go through the other statements and check...but make sure before doing this, you're more than 100% sure ....[there are questions where it's rather obvious the statement is wrong.. ]
and also if 1 is correct, dont waste your time checking if 2 is correct or not...jump on to statement 3. If you're really sure it's wrong, then D would definitely be wrong, ans will be D
and if you're sure 3 is correct then 2 will definitely be correct, and ans will be A.
May be this'll seem a bit foolish, but trust me, it does get your answers right, and also saves your time. After finishing the paper, if you have enough time, you can check the other statements etc. 
t helped me, and might help you