i just did my gcses and i got a 9 in history. I did lots of timelines- one for each chapter in the textbook which helped a lot. make notes and make sure you start your revision early! i only started revising for history the week before the exam (i wouldn't recommend this!). also do practice questions!!! this is essential and get your teacher to mark them. i would try and do at least one a day especially in the weeks before the exam.