For history A Level, I did OCR as well (Russia and its Rulers, French Revolution and Britain from 1930-1997).
I found that blurting was the most effective for knowledge. Pick a topic in a module and write everything you know (statistics, ideas, people), then look through your information and add the extra stuff in another colour. Then later do it again. This also helps get you used to writing for long periods and fast, which you need for exams.
Also, find past questions and/or ask your teachers to create them, and create plans. I create the quick plan that you need for an exam, so give 5 minutes to write down what you would do in an exam. Then create a detailed plan with information, first by memory, then by notes.
Also, if you are doing USA or French Revolution, or certain others, the Unsimplified Videos give you good background to work with. I have found there are limited YouTube channels with academic advice for A Level History, so I just ask my teachers instead.