I got all A's, except 3 a*s in english lit+lang and history, and a C in spanish
I would suggest that you start your proper revision now and it will save you a lot of stress around May-June time.
I used the CGP books for science they literally saved my life and I learnt 3 years of material for the first time in like 2 months. If you have a good memory use highlighters and just highlight key points in the CGP books when you read for the first time and then repeat the sentences out loud. Then repeat the whole section out loud until its in your head, so basically memorise it. If your memory isn't as good, then try to memorise the section then open a microsoft word document and type out what you remember word for word, then look back at the section and see what you missed out and keep working at it until you've learn it.
For maths I used mathswatch (if your school doesn't offer this you can message me for mine), and I would make really messy notes on plain paper and answer the questions with her on paper. Mathswatch is better for when you're kind of familiar with the topic already so if you know its new and you're not familiar with it, search the topic in youtube and learn it from scratch first. I started with the grade D topics and made my way to grade A/A*. You don't need to know every single topic to get an A/B grade, but the more you know the better because the A* topics you're great at might not be the ones that come up. Before I started the next grade I would print off all the worksheets, so when I started grade C, I would open all the videos in the number category (there are four categories under each grade, i think number geometry and algebra or something? but anyway) and then i'd click worksheet which is beneath the clip and print them all and then after each grade I'd do the worksheets. I think you can find the answers to the worksheets if you search mathwatch worksheet answers in google. Also for maths I'd suggest loads and loads and loadssss of past papers. then watch a youtube video of a teacher going through it. When I did my gcses in 2015 there was a channel that had all the papers and went through them but its been made private but theres another channel doing the same now called 'achieve maths'. Find a paper e.g June 2012, do it now and miss what you cant do and then learn all the grade D stuff then do it again then learn grade C and do it again then grade B+A and then again and whatevers left behind, watch the video and see what you missed out. Watch the whole video not just what you think you can't do because you'll see small marks you missed out and easier methods. Eventually I was so short of time I left mathswatch and just watched past paper solutions on youtube but you'll be okay if you start now.
I dont know what other subjects you do but for humanity subjects like geography, r.e, history just make your notes in order of the specification, you'll have time to make notes if you start now because theres a lot of material especially for history. Then write mini essays on the different topics if you have time, explain it to yourself to make sure its clear in your head because with these subjects its less memorising and more understanding. These are the kinds of subjects you can revise with other people for so maybe get a friend and ask each other exam questions and just say points you'd make to each other and keep your books in front of you to check you're right. (this is really nerdy i know but itll help you both.) Also try to become an expert at writing the answers in the format the examiners want, ask if your teacher has some example ideal answers?
For english language do lots of past papers and really look at the mark schemes in detail you'll find you you lose a lot of marks by not doing things that you didn't know were expected. Really analyse the texts you're given, I learnt that because in a past paper i did, there was a question about what a man would have had to do to ensure he would survive in [something i cant remember] and an answer was practise controlling his breathing, because of one line in the text that said 'he inhaled and exhaled slowly' or something but basically its small things that you miss and you need to write them down even if you think they mean nothing.
For english literature I had a really good teacher and she picked out every single detail of the texts/poems so if you have a good teacher who has given you good notes then you'll be okay as long as you do past papers, but if you're unsure then google some essays on characters in the texts you're doing or at some analysis of poems you're studying. Again I made notes on the themes and characters in both texts (an inspector calls and of mice and men) and i made notes on each poem (we did conflict) i think i may still have them so message me if ur interested
If you have coursework based technology like I did then keep going back to the teacher and asking how you can get it up to the next grade, ask to borrow the work of people getting A's and see whats on their coursework thats not on yours, i ********ted a lot of tech and my food tasted really bad but the photos looked amazing and I wrote a lot of technical stuff that made my cw look really good. Ask your teacher for a check list on everything you could hand in to get an A/B/whatever you're aiming for and then do it all slowly then tell them to mark it and then ask how you can improve. Don't be afraid to ask because they're there to help
I have absolutely no advice for languages I just passed because I did good on my coursework because I used absolutely all of the vocab she provided and strung together some paragraphs.
In the month before my exam I did like 12 hours of revision a day probably lol but its because I was meant to have a chilled 3 months until the exams but then i procrastinated loads and had to cram it into one month, but the only reason that was possible was because I made my notes in the christmas holidays so if you have no notes you won't get away with doing that and you should start now
Also if you have time and nice pens then make ur notes pretty and colourful because it motivates you and it makes it fun.
I didn't do different subjects each night I know that works for some people but personally I did like 4 days on b1, 4 days b3, a week maths, a week english, etc. and then after i had done it all once id start again but less days on each subject because I'd be more familiar with it. Then eventaully it was exam time and I made a timetable thing like with all the dates in the margin and then the exams in blue and my revision for that day in red. I'd revise every subject the day or two days before the exam and you wont be stressed because you've been doing it for the past few months. Try not to neglect any subject and even out your time for each one. Good luck, don't procrastinate and stay hydrated because it helps you revise for longer, and get a lot of sleep. and remember as long as you work hard now you should be happy with whatever grades you get!!