Just do tons of practice. I used to be terrible at these tests, and would never pass.
However, now I routinely get in the 85% + percentile. I attribute this to practice (and alot of it!) because I definitely did not have any natural ability in them!
So just keep practicing, and you will improve. No magic formula unfortunately, though I'm sure others will have some specific tips!
Use the free practice tests, and your careers service might have access to some of the paid ones (like they do at BPP).
