One of the most difficult things about the Driving Theory Test is the second part of the exam.
The Hazard Perception Test is often overlooked in favour of practice on the questions; this is a mistake because the second part is much easier to fail than the multiple choice questions.
Getting to 50/50 (or at least 47/50) is very easy on the questions, it involves memory and all you need to do is keep going through the questions, eventually you will remember all the answers. Repetition is the key.
Okay, so once you've mastered the questions then what do you do?
You practice the second part of the test, using practice clips and understanding how to identify hazards.
Your Hazard Perception Test Practice should be done well before your test takes place, don't wait until a couple of days before the exam because if you do: you will probably fail.
I'd recommend you practice at the same time you start memorising the questions, but if you're unable to do this then at least start getting into the clips 3 weeks minimum before the big day.
If you follow these guidelines, you should have a great chance of getting through the test, then moving onto the practical.