Micromanagement of thought is necessary in order to achieve LSAT perfection. It is almost impossible to perform the mental tasks required to score a 180 if you do not remain calm and focused during the test. Rather than trying to hide the elephant in the room, I'm going to just point it out: the LSAT is the single biggest factor in competitiveness when applying to law school for the vast majority of applicants. Yes, there are people with a 160 who are accepted to Yale every year; those people are such a small group of outliers that they don't constitute a market for a blog. For the rest of us normal people, the door into a top law school may only open with a 170 or higher.
Test anxiety is the most common reason I hear for people either not preparing for the test or performing poorly on the test day. Not preparing because you're scared is completely illogical, and thus doesn't bode well for the logical reasoning sections. As far as dealing with the importance of the test, do it before you arrive to your testing site on the day of. Speak with a counselor, meditate, pray, learn yogic breathing, or practice until you feel comfortable with any question LSAC could throw at you. Find and develop your reason to not be afraid of the test now, because a minor fear during practice could mean the difference between a 180 and a 170 when you panic on one of the logic games.
Although there is a small margin of error in the range from 165-180, that also means that there is room for significant improvement through a relatively small amount of change. It's all in how you mentally approach the test; use the small window as an opportunity and not as a cause for a freak-out. This graph I made of the June 2008 LSAT conversion chart is one of the best visual ways I could develop to demonstrate how the LSAT bell curve interacts with the LSAT scale scores. Notice the number of missed questions for each standard deviation, and how small improvements--5 questions--can boost you from a decent score--165 with 14 questions missed--to a great one--in the LSAT 99th percentile with 9 questions missed.
What's even more mind-boggling is the difference in raw numbers of test takers who scored a 175 and 180, a difference often made by only missing three more questions. A lot of students ask, "How many people take the LSAT each year?" Last year, 151,398 people took the LSAT: about 450 people scored 175 or higher, while less than 25 scored a 180. The better question to ask is, "How many people can I cut out ahead of me by improving my LSAT score?"
For example, improving your accuracy by just 4% on logical reasoning sections would improve your score from 173 to 175 on many LSATS, and would cut out 50% of the people in front of you. That 50% represents only .5% of the total number of test takers, but those ~750 people are more than the number of first years admitted at Harvard and Yale combined! Although I'll later point out that you should always be skeptical when you see percentages in the LSAT, right now, take me at face value: you are intelligent enough to twist the numbers and importance of the LSAT to your advantage, so get into Zen mode from now until you are accepted into your top choice law school.