Just to add to the above and the previous thread.
During the exam, take your time. Don't try to rush through it. Forward plan as much as you can. Think about what you are going to say before you open your mouth, and listen to what the 'examiner' is saying. Have a blank piece of paper and pen at the ready and organise the paperwork on your desk so that you can easily cross-reference (you'll have 3 bits of paper plus your own scribbles to work with).
In an effort to get mine over as quickly as possible I rushed myself needlessly, consequently, the colours weren't flying.