Problems, problems, problems, problems. I didn't do nearly enough the first two tries. Do as many problems as you can. I had taken SOPE the first two tries but decided to take EET (I think it's a different name now?) for the third attempt to strengthen some of my weaknesses. That, combined with the practice problems, pushed me over the edge.
Study environment was a biggie too. The first two tries, I studied on the couch while my husband watched TV. For the third attempt, I was much more rigorous - studied at the table with classical music to focus, etc.
Finally, I extended my prep time. I started studying a couple of weeks after my honeymoon in April 2018 until about 2 or 3 days before October 2018 exam. It never feels like enough time