This is a good point. Exactly what I did too. The second I had hit the start button I would grab my sheet of paper and spend a minute or two writing out every formula, conversion, diagram I had memorised for that particular test.
If I had time remaining I would also query any questions I thought were ambiguous or had more than one correct answer (quite a few unfortunately). Not really sure how much that does, if anything, but it's worth a shot and I'd always encourage everyone to do the same. The more people that query a question the more chance of them looking into it. You would think...