I started out testing in the 150's or so when I first took the test. When it came to game day, I got a 176. The key for me was just practice, practice, practice. I took 3 full-length tests a week, studied the answers that I got wrong, and did several other exercises a week (mainly in games, which was initially my worst section). I did this for a little over a month -- I basically devoted most of my time to it after I graduated in May (I took the June test).
But yeah, the practice helps a ton. With that much practice, it wasn't even fair to put me in the same LSAT room as everyone else. I developed a sense of intuition based on what I identified as the common tricks and mistakes of the test. The intuition was so accurate that actually doing the problems almost became a sort of backup. And I got wicked fast. For the most part, I did each section twice and still had time left over to relax. Plus, I was so used to taking the long test that my concentration never flagged. Oh and also, after getting a ton of practice tests in the 170's in the weeks leading up to the test, I probably wasn't as nervous as most of the other test-takers.
Moral of the story: however you do it, study your a$$ off! It's worth it!