I used a printable version of the group bourdon test, printed a shed load of copies of different tests (so they weren't all the same) and did a load at least once every day for months. The practice test on here is great but on the actual day you will do it on paper so get used to doing it that way. I also bought a pack of DVD's from eBay which were something like How2Become a Train Driver, Richard McMunn made them I think. They had similar versions of all of the different tests for you to practice. I actually bought these, copied the discs onto my laptop then put them back on eBay the same day and sold them for more than I paid for them so they didn't cost me a penny and were invaluable to me. I bought books of Train Driver questions too and did a lot of on line research into MMi and how to give yourself the best chance you could have of passing.
My advice, any question or test books you buy, write your answers on scrap paper. Don't write in the actual book then you can sell it on when you're done with it. That way all of these expensive practice materials won't cost much at all.
Log onto the OPC website, practice materials on there too.
One of my kids has a 'Bop It' toy. Excellent for learning to react quickly to different tones and buzzers. I used it loads until I could beat it everytime.
Download brain training and memory testing apps on your phone. Use them. Cheap (often free) and effective and you can carry them everywhere so when you're sat on the bus, in a waiting room, on the loo, anywhere - more practice.
It is true that some people have what it takes and some don't but practicing something will soon help you find out. You will either improve or you will really struggle. No one buys their first guitar and joins a band the same day. Even the best, most naturally skilled guitar player that ever lived had to put thousands of hours of practice in. You won't need thousands of hours but still, practice and preparation are key to any skill. This is no different. Its the concentration that you will find you either have or you just can't seem to muster.
That's my take on it anyway.
Hope it helps. Keep me posted on how you get on and if you want this badly enough, don't quit. I didn't and it worked.
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