Didn't bother preparing after I looked at what words would come out.
Motivation: I did Mathematics at undergraduate level, so didn't bother to study for Quantitative section. Also being an avid reader since young (read through classics, contemporary fiction, popular sci-fi/fantasy authors, Project Gutenberg), most of the words tested were already familiar. So perhaps you could say I've been preparing since high school for the Verbal part. Those which weren't could be guessed from prefixes / suffixes / context. Went by gut feeling during the test.
I was lucky during the test though - both AW questions focused on topics quite close to me - and dare I say even relevant to what I studied, so I wrote quite well.
My scores:
Verbal 163 (93%)
Quantitative 170 (99%)
Analytical Writing 5.5 (96%)
If you're an avid reader and can do maths - don't bother preparing.