Always make sure you consider several viewpoints/options.
Make references to real economists like Adam Smith, John Maynard Keynes or Milton Friedman in your answers if you can; this shows good all round knowledge of the subject which goes beyond the syllabus.
Time yourself well. I suggest you practice this using past papers.
Use diagrams where appropriate but for goodness sake
explain them.
Get in as many key terms as you can to collect those points! Again, explain them properly. For example, instead of writing this:
"Inflation is higher in Denmark than Japan . . . "
Write:
"Inflation, defined as a general rise in the price level, is higher in Denmark than Japan . . ."
One of the best ways to revise, in my opinion, is having debates about various policy options with friends who are studying economics also. For instance, pose the question: "do you think fiscal policy is more effective than monetary policy?", or "Are tradeable permits or taxes more effective at reducing negative externalities?". See where the debate goes and use the theory to back up your points.
Read the news and magazines like
The Economist so that you are up to date on current issues. In all likelihood, when it comes to your exam you will have a host of opportunities to refer to the current credit crisis and the rising energy prices or any of the other current global economic events. Also, there is no harm in talking about earlier economic history too such as Margaret Thatcher's privatisation of key industries in the 1980s.
And remember, treat the examiner like a complete dummy who needs everything explained to them.
Evaluate! Evaluate! Evaluate! This is for longer essay questions of course. One of the best ways to evaluate is in considering long term/ short term implications of policy decisions. Market solution or government intervention? Etc etc.
I think some of the key issues to be clued up on are:
Globalisation and its implications.
The credit crunch.
Rising energy prices and possible solutions.
Whether the free market is more effective than intervention generally.
Hope that helps! Feel free to PM me with any questions.