I used The Official DVSA Guide to Hazard Perception DVD-ROM. RRP is £15.99 but it’s available on amazon prime for £11.35. The hazard perception test is just a computer game really, so takes practice to work out the technique that you need to use. Find out how many clicks you can use. Sometimes you might want to use 2 or even 3 clicks. But you mustn’t use more clicks than you’re allowed, otherwise you get zero points for that clip.