I've been doing some AP Lang prep through the college board AP Classroom assignments. I think the most helpful ones have been the timed writings. The FRQ is at the end of the test, and that's when I'm the most tired. So, my writing would obviously suffer, and also the writing is just different from any other kind of writing assignment: it's essentially a rough draft, and you are also timed, and can't take too long to plan it out. That's why I think it's so valuable to have timed writings, because it gives the most valuable experience for test day. On the other hand, the multiple choice practice problems have also been helpful. They are a lot like SAT questions. The UI is so similar because they both use bluebooks, and I'm pretty sure both APs and the SAT are administered by the same company, CollegeBoard. They include some comprehension questions, and also some grammar questions – even including the "no change" option. So, since I already have a lot of experience with these types of questions, I don't think the AP Lang test will be that hard, especially considering that most high schools offer it junior year rather than senior year. So, in conclusion, the practice problems have been really useful for me. Also, another AP test-taking strategy I've found really useful, especially for English tests (like AP Lit as well), has been to just take a practice test a few days or the day before the actual AP test. There isn't much "studying" you can do for English tests, in my opinion, because it mostly tests the skills that you need to build up day after day, rather than knowledge you can cram. So, the best thing you can do for yourself is to get a feel for the test format, and know what to expect.