Do you know which particular part of verbal is giving you the most trouble?

For sentence correction, the key is to know the six or so major grammatical errors that show up all the time - COLD. And, be able to spot them in a sentence without even comprehending what the sentence is talking about (e.g., when you see the word "it" in a sentence, you know there might be a pronoun issue - you don't even need to know what the sentence is about).

For critical reasoning, practice IDing conclusions, premises, and assumptions in arguments. Spend a lot of time analyzing the right AND wrong answer choices, and make sure you know why EVERY answer choice was right or wrong - don't be content just knowing why the right answer is right.

For reading comp, practice reading passages for the main idea, structure, and purpose only. Learn when to skip over details - you won't be asked about most details in the passage, and they will only slow you down and confuse you.

Good luck!