Start off the school year by taking down as much notes as possible in class. Make sure they're clear and readable, they don't have to be colourful or highlighted at this point but you can if you want to.
Next start attending revision sessions as soon as they are put on. Some of your sessions will clash, so either alternate it between weeks (this week I'll go to Computing next week I'll go History) or work it out logically e.g. if there are two History sessions a week and only one Computing, go to one Computing and one History if the two clash. At this point you want to start putting those gel pens at the bottom of your Christmas stocking to good use now, as colour, especially bright ones, helps you remember it more. Bring chewing gum along too, don't make it obvious if you're not allowed it but surprisingly chewing gum helps with your memory (found out on a Matthew Santaro video). If you're a focused pupil sit with your friends wherever you want and take down your notes, but if you're easily distracted, try sit nearer the front away from your chatty classmates.
There are lots of revision techniques out there so let me run you through them:
~Flash cards are highly recommended. Start making these as soon as you can otherwise you won't be able to finish them. These are especially good for Science, Geography, History and ICT, although they work in most subjects. I would suggest making your own instead of printing them off online because you learn it better writing the information down than seeing it and also some online flash cards are inaccurate to your specific course. I would recommend using coloured card using different colour pens. If you want to write on the back, avoid sharpies. Also use a highlighter to highlight key information.
~Mind maps I would recommend for key words in subjects like English, Languages and Business Studies. Select sub-topics and make a map about all the key words/key information you need to know about it. E.g. in Business, pick the sub subject Marketing, and write important details about the Product Life Cycle, Boston Matrix, Branding etc. If you have blu-tack, hang these up on your bedroom wall and around the house (with permission from your parents!) so that you remember it. These are good to do at the start of the GCSE process but also is a really useful as a quick revision tool before an exam.
~Youtube videos are a great newer tool to help with exams. It's important to pick a youtube channel(s) that works for you, if you hate the guys voice you're not going to take the information in. Pausing to take down quick notes is suggested but not necessary. These are best towards the middle end of your exams on topics that you particularly struggle on. (Make sure it is the right exam board and year).
~Websites is another newer tool which is helpful as it has all the information you need. However, finding the right website is the most horrible experience so you need to find one early on. Do not copy the information word for word or print it. Instead, try and write it in your own words so you understand it and take it in. Website Recommendations:
1.)
http://www.bbc.co.uk/education/levels/z98jmp3 - Of course I would recommend this gem of a site. They also have an app now which has flash cards for your revision before the exam.
2.)
https://mathswebsite.com/ - There are lots of good maths websites e.g. my maths and Manga High but this one is my favourite. Don't let the ironic name trick you, Hegarty Maths is a very useful website. It has access to all past papers for different exam boards and mark schemes, lessons on there and separate exam papers for different maths subjects e.g. Pie charts. The best feature is it has youtube videos talking you through every question you do in your past paper packs, and it splits it up so if you found question 3 easy you can skip it and watch how to do question 4.
3.)
http://www.coolgeography.co.uk/ - I know you're not taking Geography but for your friends when you can't find it on bitesize look here!
I didn't rely on many websites because inaccuracies.
~Textbooks are good if you can afford 11+ books. They can also include a phone app which you can download too. I would recommend the CPG guides if you're doing AQA and edexcel for edexcel. AQA textbooks are a bit poop, but AQA CPG guides got so many of my friends through GCSEs. Like with websites, write notes down in your own words from the books. Also, after a revision session, read the topics your teacher has gone over so they sink in.
~Past Papers I left until last but these are the most important. You can usually get them from your teachers or your school website. If not, check your exam boards website. They'll have some there too. Start past papers after the notes process, usually happens between February half term and Easter when people start. MAKE SURE YOU TIME YOURSELF especially for English Language. You will run out of time in the actual exam otherwise. You can go sub section by sub section or just paper by paper. If you do not come across a question in the past papers e.g. Pie charts, either research questions on it or get your teacher to design some questions. If they decline, go to your Head of that subject and ask them. They will do it as well as giving that lazy teacher a kick up the backside.
And that's all I can think of right now. Don't leave it to last minute, but don't forget your family and friends. Your friends are going through what you are and know how you feel. And your family (majority of the time) are behind you. Hope this helps
this was so long to write