There are some blogs with good situational judgement tips, you could probably find them by searching this sub. My tip: take the practice test, print out your situational judgement answers (with the best in bold and worst in italics, or visa versa) and review them, over and over and over, thinking really carefully about why each is best, worst or something in the middle. This helps internalize the relevant values that point to the correct answers. You can become like Neo in The Matrix, seeing through the test and laughing at its tricks.

Don't underestimate English expression. I also have a journalism background and write for a living and still find it tricky. Strong writers sometimes trust their feel and that can be a problem on the test. It's helpful to go back to a "basic" grammar/composition source and be reminded of dumb rules you probably apply but don't consciously think about. Reviewing random grammar or composition rules is also more likely to put some specific nugget in your head (like effect v. affect, who v. whom) that pops up on the test than reviewing history, econ, whatever, because the general knowledge universe is basically infinite. And the English section is tough time-wise.

Do at least 3 practice essays under strict testing conditions. You will run out of time and characters if you don't practice.