speedbird1t
they should give you a pencil and an eraser for the cube test. Some of the people at my testing day drew the cubes on the eraser to work it out. However, it may slow you down and is dependant on you getting the pattern right. I found the easiest method is just to answer all the tests without relying on any tricks. Looking back though, had I known what was going to be in them I probably would have practised them a few times beforehand. Like IQ tests you tend to get better the more times you do them. Also, rather than 'getting passed' the tests you may develop some of the skills/mental dexterity they require.
Hope this helps