What does "test prep" consist of, anyway?

I am a professional test prep coach.  I help students prepare for their college entrance exams.  (I should also mention that I tutor students in math in case you are looking for a math tutor.  However, most of my students are preparing for the SAT.)  The mainstream media seems to find my profession offensive in the extreme.  Test prep coaches are accused of either charging big bucks, but having no beneficial effect whatsoever or charging big bucks which gives wealthier students an unfair advantage.  Sometimes an author accuses my profession of both of those things in the same article.  That's always good for a chuckle.

In most articles or news features you'll hear that students (either unsuspecting and being taken for a ride or filthy rich and taking advantage) are spending "hundreds of hours and thousands of dollars" on test prep.  Not with me they're not.

I belong to a Linkedin group for test prep coaches.  A few months ago, someone posted a poll.  "How many hours do you typically spend with a given student?"  Most people responded with answers ranging from 5 to 20 hours, which suggests that this "hundreds of hours" business is the exception rather than the rule.  One tutor responded with "over 100 hours."  The reaction was swift and incredulous:  "WHAT THE HECK ARE YOU DOING WITH A STUDENT FOR OVER A HUNDRED HOURS??"  (Further evidence that the "hundreds of hours" thing is the exception.)  His answer:  "Teaching kids in China how to read and write college-level English."

Oh. Ok.

When you tell people that you coach students for a standardized test, they seem to think that you spend your time showing them how to color in ovals really, really well.  Or perhaps teaching them special tricks that will enable them to correctly answer questions without actually knowing anything.  Like, "if you've bubbled two C's in a row, the next answer will always be B."  (No, that's not an actual thing.)

My clientele are mostly strong students who just need a little bit of review.  However, sometimes I get someone who somehow missed out on basic grammar.  We might spend A LOT of time together.  And we call it "test prep" because if I hung a shingle that read, "I will teach your kid basic grammar," no one would call me.  Just as in China it is apparently easier to get clients for SAT prep than for lessons in reading and writing college-level English.