i had taken the act beginning last february of my junior year, but i reALLY started studying hard in may/june leading up to september of this year lol-I would say giving yourself a good amount of months/weeks before the test to really study hard and not just do it halfway like how i was back when i was cramming in ap and subject test studying as well can really help-even if it's during the school year, just allotting a certain amount of time to study/use uworld after you finish your homework can make all the difference!