For maths, print out all the syllabus and content for your exam board. Highlight topics you know everything on in green, feel okay in yellow, and topics you don't know in red. Revise all the red topics first, maybe by watching Corbett Maths videos or using MathsWatch, or simply just asking your teacher to help with a particular topic. If you can't print the syllabus, reflect on your mocks and identify target topics that way. But after you watch videos and seek help on those, do practice questions only specific to those topics, Corbett Maths and physics and maths tutor and mathswatch give you questions regarding 1 specific topic, so do topic tests and then they have an answer sheet so mark them. In the end, do loads of past papers and questions as for maths practice makes perfect, do a little bit of maths everyday attempting questions.
I got a grade 9 for gcse aqa english language, so therefore currently I am doing A-Level AQA english language. So, let me know which particular question confuses you