To play it safe, stick to real examples drawn from your studies (history, literature, science, etc.). Make a list of 5-10 topics you could write about. Include a paragraph for each topic on your list that describes that topic in detail. Review this list a couple of times before the test so that these details are fresh for test day. I describe this process, along with other tips for the SAT essay, here: .
The top 10 tips for the SAT Essay