Study A-level mathematics techniques and procedures before you design your curriculum. Often, A-level math courses must be fast-paced, with time to review material with students toward the end of the course.
Explain to your students the difference between a normal math class and an A-level math class. Explain thoroughly what will be expected of your A-level students academically and behaviorally. Be honest about how much work they will be expected to do and how difficult the work will be.
Review class procedures, methods and objectives with your students. Hand out syllabi or schedules so they can anticipate, keep up or work ahead if they desire. Ask your students for questions on how the course will be taught and be prepared to answer them.
Keep up a fast pace as you begin to teach your students so they are aware of how quickly you will be moving through material and how alert they need to be.
Keep in mind that your students may not fully grasp the A-level math material as you teach it to them. Give them practice worksheets and assignments and consider putting them into study groups so they can grasp the information as you move rapidly through the curriculum.