Theres a lot of people saying the tests shouldn't be practised. I disagree. Before I was a Driver I saw the tests as just an obstacle just like any other. The way to pass was by practicing. The practice I did was extremely effective and I passed through practice & more practice. Without practice, I would have failed, as my first set of results on the Group Boredom/Reactions software were very poor, and my mechanical comprehension is appalling (I struggle like you would never believe at anything mechanical e.g. maintaining a bicycle)
Note that these were the old pre-2013 tests that I sat. The new ones are different.
Anyway, here is a breakdown what I did in my practice to guarantee that I pass despite not having the natural ability:
Group Boredom Test: Downloaded the Group Boredom Practice Tool. Appalling results on my first attempt. Several attempts later and I could breeze it without even thinking!
Reactions: Downloaded the practice software which replicates the real thing. I was very slow and inaccurate at first. A few weeks later after some serious practice I was hitting everything as fast and as accurate as professional typist on a computer keyboard!
Dials: I didn't practice this, but this test is really easy so it doesn't matter.
Mechanical Comprehension: (MT4.1) - I asked people who had recently sat the test what sort of things they were asked about. I then researched about those things and it helped immensely when it came to sitting the tests!
Trainability ('Glop') - I asked people who had recently sat this test what was in the passage about 'glop'. I then noted it all down and got it all into my long-term memory. When I was going into the test centre I knew what I was about to read before I even read it! Easy.
Structured Interview: They always ask the same five questions so I just found out what those questions were and made sure my answers were as good as I could get them.
On this interview you will probably get caught out if you completely make something up, but you can get away with exaggerating your answers.