I'm bored, and I feel like throwing some random advice out there, so I'm going to go for it. Although unsolicited advice has earned a bad rap around here, the extent of my boredom probably justifies this thread.
1. Take a long bath during the night before the test. You'll feel very relaxed when you fall asleep.
2. Teach the LSAT
. I can't bold this point more heavily. I would probably be in your shoes if I hadn't spent hours on this forum explaining problems and realizing my mistakes along the way. It doesn't matter who you teach, but do teach, because you'll see things that you didn't see when you didn't have to articulate your mistakes so clearly.
3. Don't expect to see a certain section first, or, if you do, let it be the one you least like. There's nothing worse than expecting LR and seeing RC, which may be the bane of your existence.
4. Find a test center with a comfortable table. This may not seem like a big deal, and visiting test centers shouldn't be like visiting schools, but you don't want to be uncomfortable during the most important three hours of your apps cycle. At my alma mater, they put students in a large hall where the desks were too small for both the answer sheet and booklet. That's a big deal.
5. Turn the world around you into the LSAT. If your girlfriend argues with you, think of her arguments in terms of conclusion/premises, conditionals, weaken/strengthen, paradox, and even "argument presumes without justification." Yes, your friends and family will hate your sudden argumentative nature and damn good logic, as I can vouch, but it doesn't matter because the law is your family now. Do you have six tickets to a ball game? It could be a fun time.
6. Never settle for guessing. If you picked B over C for no explicit reason and got lucky on a practice test, you should count it wrong. That'll give you a much better idea of your aptitude.
7. Everyone handles the LSAT differently (just like law school). Because your drinking buddy tells you that his cousin took the test on a whim and scored big bucks because of a "high" score -- whatever speculative nonsense that is -- that doesn't mean that you'll do the same. You may have a friend that studies only an hour a week and he's still nailing games like a savant each time he does a PrepTest. That may be true for him, but it's not true for you. Put in the maximum effort, since naturals rarely live up to their abilities at the kitchen table come test day.
8. There are plenty of horror stories out there. Save them for after the test. You're you and you're on LSD, so you'll probably do very well. Just because someone threw up all over her test booklet and scantron, it doesn't mean you need to hear it. I can't stress this point enough. Never ever listen to a horror story before the LSAT; you don't need suggestions. Three days before my test, I read a story about a Tier-II graduate who jumped off of the Empire State Building after being suffocated by student loans, and, unfortuantely, I've never fully stopped shaking because of it. I'm going to a top school next year and I still don't take anything for granted.
In fact, don't go over to any of the other forums before the test. Period. You don't need to know about how "the horrors of the non-T14 JD market."
You don't need to decide between Harvard and Columbia with the Hamilton . . . yet.
9. Finally, don't ever forget that, no matter what happens, you can always re-take (unless you've already taken the test twice). Don't think of this test as a one-shot deal, but, rather, as a learning experience. There's always another cycle; there's always another LSAT administration in three months. Take a deep breath, focus, and good luck.