In addition to what Stevie says above, the only tests you should have any sort of look at are the 'games' on the NATS website. They may/may not be accurate to the Stage 2 tests but what they will do is get your mind into the right mindset. That said, don't go overboard on them, use them to get your focus going - there's only so much you can do before you potentially make your brain go in the wrong direction...