I have just finished a degree in a humanities subject. I did better in every single exam than essays but I found a way of revising that worked really well from very early on. On the day of my final exam I was sat having coffee with the school mums and they couldn't believe I could be so relaxed. Everyone has a slightly different way of learning but my strategy for exams is as follows:-
Step 1 locate past exam papers if they exist. Work out which topics are of particular interest and see how often they come up. Select revision topics. I had to answer 3 essay type questions in 3 hours so would try to pick 5 topics because this allows for a tpoic to be missing but also means I can give enough time.
Step 2 find the essay questions relating to the topics, get all your reading together. This should include all of the required reading and your notes from lectures etc.
Step 3 re-read lecture notes with a large piece of A3 paper and have pens/highlighters to hand. Title of topic in the middle and then as you read your notes write each unique point separately with any relevant quote etc next to it. These will become your headings and sub-topics to answer your question.
Step 4 Transfer sub headings to their own piece of paper and when reading make notes - but only on the relevant piece of paper. You have now thought about those topics twice. If they can be split into sub headings then do that.
Step 4 Type all those notes up. You are now looking at this info for the third time.
Step 5 Take one set of typed notes and pick an exam question and write an answer in timed conditions with your notes in front of you. Use them as much as you want.
Step 6 transfer those notes to record cards (fourth time) allowing yourself no more than 10 record cards and no more than 4 points per card.
Step 7 Look at those cards whenever you can. Just before bed, when making a cup of tea, on the bus. Use them as prompts. Ask someone to hold the cards and read the title of the card, this should prompt you to recall what is on the card. The info on the card will be limited but
e.g. The card might be ...
STALIN
Culture
Quote
Socialist Realism
So you would be prompted to recall some stats/quote that is the card and perhaps talk about it in more detail because you have been answering practice questions. Its deisgned to help you recall what to cover.
Step 8 until exam day just keep doing a practice question here and there.
Most important just be calm and answer the question.