To score good bands in all the four modules, the best approach is to understand the strategies of different questions in each module, for instance in the listening test for MCQs try to make notes to get the right answer. Moreover, in the reading test for True, False and Not given Questions use the technique of comprehending. Likewise, in the writing and speaking tests, use a range of words and structure your ideas logically.
Furthermore, practice all four modules equally and as much as possible.