I really don't know how one can prepare. And after talking a bunch of old retired FSO guys recently, they agreed. Either you are genuinely interested in international affairs and you read the news regularly and digest it - or not. That seems to be all that the test confirms. I did not look through any study guides or practice exams other than the one posted on the website, which was more difficult than the real exam. The real exam was so ridiculously easy that I thought I was misreading the questions. Where they really weed you out is the oral exam - which you also can't prepare for. I think the best advice is to simply be confident and recognize that if you don't "pass" you can take the test again and again and again.