Hello! So the best advice I could give, and it is also the best advice I have gotten from my classmates who passed;
Take your time.
I went through the questions I got wrong from UWSA; word by word, and I went through the chapters in First Aid, slowly. I really feel like it is important to distinguish the right answer and the answer that look very similar to the correct one, but it is not. I wrote it down in my little Uworld journal; a Word doc that contains all the questions I got wrong. NBMEs are the great predictor of your actual score. Go through all the questions you got wrong, and understand why you picked the wrong answer. If I could go back, I would definitely try out more NBMEs than UWSA. Afterall, they're the ones preparing the exam questions, no?
Have a look at Online Med Ed, I cannot stress this enough, how key those videos are for my CK prep.
Dr. Williams will explain to you in a very elegant and simple way on how to distinguish the right answer from the wrong one.
Also, no book is superior than the other. It varies between individuals. I have tried Secrets, I tried MTB, I tried SUTM. You name it, I have tried them all. But to me, First Aid is so complete. You will not go into the exam and wondering "I don't recall reading that during my prep." SUTM is comprehensive as well, however, considering most of the facts are in bullet points, I don't find them that attractive to read. Again. Book choices depend on the individual itself. Some pass with MTB and Uworld. Some pass with SUTM. Find what works for you. And memorize the book.
If you're an IMG pls spend at least 3 months or more on prep. I was so impatient before, and my parents were pushing me to take it earlier, but I know, I was unprepared. I heard so many horror stories from people who failed, some failed twice. Don't rush it. When you're ready, you will know it.
Anything is better than a fail.
Best of luck!