In my opinon, what helped me get an A in Geography - obviously this depends on your exam board - but firstly ensure you have the knowledge. You can consolidate your knowledge through summarising what you have learnt after every lesson, using flashcards and mindmaps. Blurting is one of the best methods of active recall that I would highly recommend. After you feel you have the knowledge on your topics, you should practice applying it. Answer exam questions. Then get them marked and redo them to get higher marks. One you feel as you know how to answer a large range of questions - and well - then start to do the papers in timed conditions.