If you're taking it next week - not much left you can do.
Taking the prep classes was critical, I thought. Esp. taking the past exams that they give you to practice on.
No surprises that way. I scored fairly consistently on those practice/past exams, and my score on the real one was similar. (Actually a bit better than the practice ones - I focus better under pressure).
I found that the LSAT was definately "masterable." Unlike a lot of other standardized tests, it doesn't require any prior knowledge of anything (which is why so many ex-pre-meds, philosophy majors, etc. end up taking it). I thought it was kinda fun, and it definately was something that was right up my alley. (96th percentile, thank you, thank you very much!).
I took the old one, though, a long time ago. (Has it really been 17 years?!?). People were probably dumber back then.
P.S. The night before I took it, some of my sorority girl friends thought it would be a laugh riot if they set off my car alarm in the middle of the night . . .