On the day of the LSAT, you should only have to worry about at most one thing--the LSAT. To minimize your chances of having other things to worry about, prepare in advance by doing all of the following and more:
Circa one week before the day of the test, read DAY OF THE TEST. Read it all except for omitting exactly one of Test Centers Outside the US and Caribbean Test Centers Within the US and Caribbean.
Have a Plan B for getting to your LSAT Center on time.
Candidates should expect the LSAT test day to cover up to seven hours.
Consider the route to your testing center suggested by your GPS, mapquest.com, etc..
If you have never driven the route that you plan to take to your LSAT test center, make sure that you take this drive at least one week prior to the day of the LSAT (preferably on the same day of the week that the LSAT is given; perhaps at the same time of day too).
Allow plenty of travel time so that you arrive early at the LSAT. .
The evening before the LSAT is a time for relaxing, not for cramming or partying.
Be aware of the weather forecast for the day of the test.
On the night before the LSAT, plan on staying at quiet hotel or motel (hopefully one within walking distance of your test center) if the alternative is a long drive, traveling in an unreliable car, traveling in inclement weeather, etc,..
Set at least two alarms and, if necessary, ask someone to give you a wake-up call. .
Do not go to the LSAT hungry. Have your usual breakfast but, if desirable, slightly augmented. Allow time for a leisurely meal.
The room in which the LSAT is given may be too warm or too cold for you; dress so that you can be comfortable in all reasonable room temperatures.
If prior to when the LSAT is to be given, you believe that health problems, lack of preparation, serious personal problems, etc. may affect your performance on the LSAT, consider not showing up for the LSAT that day.
COUNTDOWN TO TEST DAY gives a procedural checklist for the weeks leading up to your LSAT, for exam day, and for the weeks that follow your LSAT. Just schroll to the top to begin.