I'm an A2 Edexcel Physics student so I'm not 100% sure how exam boards differ, but grasping concepts is pretty uniform through physics.
I always felt like I never quite understood what was going on or why things happened, once I begun using the techniques outlined below, for me everything fell into place.
Tips
1 ) Learn the theory solidly. Use flash cards, posters and as many good books that you can get your hands on. I use 4 different books to study from, each has their own slightly different styles of teaching or explaining the concept so I maximise my chances of finding one that best suits me. Usually, after getting my head around one the other make sense.
2 ) My most important tip is to draw out and understand every mechanism/experiment you can come into contact with. I had a small booklet, full of around 50 experiments for my AS level exams. Each showed all the equipment use, what happens at each stage, what this means and why it happens.
From understanding as many scenarios as I could, once in the exam they just reappeared, with slightly different wording or situation but the theory was exactly the same.
3 ) Assemble prompts and answer. This is my most effective and efficient way of learning. Once I have many pages of notes accumulated from my time studying, to revise I would build a small booklet with questions and answer in. This covered the main points of the theory. Re-trying the questions which covered the main points, testing myself until the answers stayed in my head and highlighting and going over the ones I tended to keep forgetting until I memorised them.
I add to this as I do past paper questions, around 1 month from the exam date putting emphasis on my mistakes.
4 ) Answer as many questions as possible and analyse the ones you get incorrect. Understand why you got it incorrect and learn from them.
I'm not the best at explaining things, but what I said above managed to steer me towards a 96% average at AS, with 120/120 in my unit 2 exam. So put faith into what I say. At first anything unfamiliar will seem very hard, but once you get your head around the concepts, in my eyes Physics becomes the easiest A-level.
Any questions feel free to ask.