I took the test in 2015 and found that the most important thing is to practise. For the situtional judgement it may be usefu to familiarise yourself with some common ethical topics but after doing a lot fo practise questions seem to repeat themselves! As for the other sections the most important thing - like I have already mentioned - is practise! Tackle as many questions as you can before the exam and try to do them under timed conditions. It is useful to come up with tactics for combatting the time restraints to ensure you gain the best score possible.