Some recent questions I have produced have come from simple ideas, possibly just one word, thought of in all sorts of odd places. Find out how many things you have to do. Don't read the qustions casually. Find out as much as you can about how much you have to do for every part. There's not much joy to be had from a question which you start well, but because you didn't read and analyse to the end suddenly turns nasty.
Many candidates forget and think that the answer to the calculation is the end of the matter.
Use the time wisely and do not waste the opportunities it offers.