Do lots of practise questions, and run through the full test papers that they give, and time yourself. Exam technique is important, make sure you keep an eye on the time, and make sure you answer as many questions as possible in the time that you have. Find a method that works for you, some sections you may apporach differently. Try to read through the text first on the verbal reasoning section, but if you cant read fast enough, skim it for the words in the question. For the SJT section, read the GMC document good medical practise, this will prepare you well for interveiw.