1. Figure out how much time you have to the actual test
2. Spend a day or two going over people's posted solutions on here - to give you an idea of how things should look etc.
3. Read AND write down everything in the program (the writing everything down part won't be necessary on the actual exam)
4. Attempt your solution and post on areforum.org/. Don't be afraid of making mistakes. The mistakes I've made on the vignettes when I've posted them on the forum have 'stuck out' in my mind and helped me even more to avoid those mistakes on the actual exam.
5. Re-do your solution with everyone's comments in mind.
6. Spend the time after you've re-done your solution and a week before the acutal exam to critique other people's solutions. Espeically on those errors that have been made on yours. This will help to reinforce understanding the concepts of the vignette.
7. Re-post your solution on here. I think at this point all your bases will be covered.
8. Test day: Use the sheets of paper they give you. Write down critical information and sketch. Use every minute possible. (You paid to sit there didn't you? Make the most out of it) Go crazy and check everything with sketch circles and lines - if you have the time to. Draw diagrams (espically in the structure vignette) and double check.