Work through at least 2-3 problems every day. Consistency beats cramming every time. Focus on understanding the process, not just getting the right answer.
The AP exam heavily weights free-response questions. Practice explaining your reasoning clearly and showing all your work step by step.
You have a lot of space. Don't be afraid to ask your proctor for more paper. DO NOT BE EMBARRASED TO USE YOUR RIGHT HAND RULE IN YOUR EXAM ROOM. Your score will do the talking.
Practice with a timer. The new AP exam format has 80 minutes for 40 multiple choice questions and 100 minutes for 4 free response questions. Learn to pace yourself accordingly.
Always check that your units make sense. If you're solving for velocity, your answer should be in m/s, not m/sĀ². This catches many errors!
The best way to learn is to teach. Explain concepts to classmates or family members. If you can teach it, you understand it.