Filters:
I think I do things on an intuitive level quite a bit when it comes to verbal. I often find that I will have circled an answer without even having a clue of why...I just "know" it is right. The good news on this is that it leads to finishing the test with a lot of time to spare; the bad is that I usually have to go back and double-check my answers on a number of questions b/c I might have been reading carelessly.
The main things I try to look for are:
1) high-level distractors: answers that sound fancy and impressive, but don't really make any sense
2) opposites/distortions: answers that are relevant, but when you read closely involve some twist or even complete 180 on the real answer
3) outside infos: drawing from Kaplan here, but whatever. I had problems, particularly with psych passages, where the answer would contain a fact that I knew to be true, but really had nothing to do with the actual question.