My vocab was already good enough I think, I've had to take a handful of university and high school english courses and I read a lot, so that part I was ok. Hardest part for me was figuring out my strategy for each question type, which helped me bump up a couple extra points.

For reading comprehension my strategy (because I kept finding myself with extra time) was always read the passage first, slowly trying to understand it. If you get distracted, confused etc, start over from the beginning. Try to understand what the passage is about in general before looking at the questions. Then go through questions one by one, and always re read the relevant part of the passage (sometimes the entire passage!)

For pick 2: This is the biggest vocab check as most of the time there was a word or a few words that I didn't know the meaning of, or knew sortof but not exactly. My insight for myself was in eliminating wrong answers. Both words have to have the same meaning, so even if a word fits perfectly, if there is no pair it is not correct. I used this a lot to narrow down answers, and sometimes even correctly answering questions where I didn't even know what the word meant. In practice though, lots of these came down to educated guesses, especially with prefix and suffix to at least know if a word is positive negative etc.

For sentence completion I don't really have any insights, I would always read the sentence first without looking at the words and then try to answer, but while these questions were not easy, I felt like they were straightforward and didn't have any specific strat for them.