Yeah, I'll admit I don't really know how I do it, but here are my thoughts...
In terms of material, I went through the MPrep course, and after that did primarily
OG and the special
OG verbal book.
For time management, I find that some questions are incredibly easy and I can do in ~20 seconds. Most questions I do in ~1 minute. I plan on about 1.5 minutes to read any passage (mprep suggests 2-3, I am a fast reader, to improve at this read the NYTimes and WSJ every day). This leaves me the ability to spend even 3-5 minutes on really tough CR questions. I finished this most recent test 12 minutes early as well.
I was doing mprep tests in the beginning but switched to official practice only. My official practice scores were all about 44-46, 48 is the highest I'd ever seen.
It's my impression that to get a score this high you have to get almost every question correct. On my last practice I answered only 5 incorrect and got a 45 or 46.
In terms of strategy. For SC, make sure you know the basics of parallelism, ", which" structure and comparisons (i.e. don't compare a review of books to books themselves), both X and Y, neither X nor Y, "that" structure, complete clause after ";", -ing clause must immediate precede what its modifying, "being" is always wrong. Don't waste time learning the fancy names for them, I literally have no idea what a participle is. Just learn how the language should flow.
First step, quick glance at the first split to get they lay of the land. Next, slowly read and
figure out what the sentence should mean. Attempt to apply the rules above while maintaining some kind of real meaning. Many answers will be wrong for some complex grammatical reason but really just don't mean anything the way they are written.
Most difficult sentence correction questions are just variations on this theme with large quantities of information. Learn how to focus on the phrases in the sentence that matter and ignore the rest. I put some idioms to heart but it is so rare to see them repeated that I'm not sure it's worth it. Then when all else fails, I listen to my ear if I have to.
For CR/RC, most important is to know exactly what the conclusion is. Boil it down to "because of X, Y will happen" With CR I try to picture the people/scenario in my mind very visually and then go over each question option and imagine it playing out, and I figure out if the result answers the question. Most CR answers are easily ruled out for either:
1. Doing the opposite (make the point stronger not weaker)
2. Being irrelevant
3. (Harder) affecting part of the argument, but not the right part, FOCUS on the the conclusion and do not be distracted.
4. (Harder) being to big a claim. Words like "always", "in general" "most" are red flags. The result should be very focused.
Get rid of these options quickly and then really think through the rest.
For RC, read the passage like you will have to summarize it for a friend later. This will help you get the broad strokes in. For any specific question, use your SC skills of reading only what matters to quickly distill the ideas relevant to the question. Then use your CR skills to find the answer hiding out there.
Verbal to me is much easier than quant (even though I'm an engineer, weird). The answer is RIGHT THERE staring at you. You don't have to do any long division to get to it. They will try and trick you, just know the tricks they use and don't be fooled.