Alternative approach to GMAT SC? MGMAT not helping much.

I think the biggest strategy is to see reasons for why the seemingly unique decisions (whether vs. if, etc.) are correct/incorrect, as there are just too many little rules to know well enough to do well with them.

Even "debate about whether" vs. "debate whether" - this one to me comes down to the ideology of "why add 'about' if you don't need it?" Redundancy or wordiness are...I guess you'd say "values" that are commonly tested (well...brevity and concision are the values), so when you're making that decision you should be able to fall back on guiding principles and not one-time rules.

I think you can see math the same way - I was tutoring last night and a student asked me about about the equilateral triangle area formula (which is [s^2 * sqrt3]/4), and I had to admit that I don't trust my memory to just spit that rule back to her. I do know, however, that an equilateral triangle will divide into two 30-60-90 triangles for you to find the height, so you can then use the side ratios to prove the area "formula". Right Triangles are a geometry guiding principle...you could memorize individual rules, but I definitely don't trust my long-term memory to remember all of those rules exactly, but I do trust my problem solving ability to figure them out if I've seen them before and understand the strategic principles behind them.

As a study strategy, if you can see smaller decisions as components of the larger strategies and prove the reasons behind them to yourself, then you're not learning a series of seemingly arbitrary, disconnected rules, but rather solidifying some larger strategic concepts. The "trick" behind these questions is usually the test's ability to make you think that each decision is unique when in fact it has to tie back to a larger concept...that's the "standardized" in standardized test.