How many are you narrowing down to two choices? If it's 25, then 6-9 wrong is a pretty good result and the problem is that you're ending up with too many you're unsure of in the first place. If it's 12, and you're getting more than 50% of them wrong, then yeah, there's not much you can do but follow the advice here.
If you're consistently getting more than half of your guesses wrong in a way that can't be due to chance, then you would probably improve more by just straight guessing—like always picking the first of the two answers—than by trying to reason it out.