1. Experiment with different methods of learning/study. eg, Talking to yourself, drawing diagrams, making timelines.
2. Develop an interest in the subject/motivation. If you aren't interested then you aren't going remember anything or much at all. As you know, with your own hobbies, you develop quite a knowledge base over time because you actually have a genuine interest.
3. Dot-point summaries/covering syllabus before it's taught. So when it comes to doing the topics, you already know it and is then being re-inforced.
4. Revise consistently over the year. Exposing yourself to material covered earlier in the year over the the entire course. Instead of your knowledge being housed in your short-term memory (cramming), by repetition, it will become long-term.
I made a conscious effort to find out what the secrets are, this year, by experimenting with different learning/revision techniques myself. A lot of it has already been said by others in the post. In the end, you know yourself better than anyone, and only you can decide which is best for you.