Always read the rubric (i.e. the text that is on the front of the paper). It is there to help you understand the exam better.

When answering questions, try and be as clear and detailed as you can. Examiners don't try to trick you out of marks, they actually try to give you marks, but only if you can demonstrate you've actually earned them.

If you think you don't know the answer to a question, sometimes you might not understand what the question means, in such instances  write what you think the question means, and answer that.

Examiners are people, not machines, and the award of marks for a question is based largely on their experience as to whether you understand a subject enough to answer the question asked. If they can understand your concerns, and the answer you've given, then more often than not they will award you at least some of the marks. However, don't abuse the idea - if you try and answer your own questions that bear no resemblance to the question asked, then you will be penalised.

Remember that these tips will only help if you've done solid revision before the exam itself.