Are you pounding your forehead to your desk after taking your third practice LSAT of the day and not seeing any improvement? Okay, first off, take a break. Calm your nerves. Drink a tall glass of cold water. Feel better? Okay. Though your LSAT prep should be comprised of many, many practice LSATs, it should not be only comprised of them. I commend your work ethic and perseverance if all you've been doing is LSAT Prep Test after LSAT Prep Test. You have the right idea, but I think if you throw in these few things every time you finish a practice test, you'll be well on your way to a higher LSAT score and less head pounding, which, incidentally, will lead to less headaches.
Every time you finish a practice LSAT, the most helpful thing you can do for yourself is to sit down and analyze it. GO through the questions you got incorrect and see if you got it incorrect because you didn't understand it, you rushed through it, or you guessed. Identify where your weaknesses lie. Do you need more focus on a specific section or question type? Or do you need to work on your timing so that you are not rushing or forced to guess on questions at the end of each section?
You also need to go over the questions you got right. Going over these questions is just as important, if not more important than going over the questions you got incorrect. Why? Well, you obviously did something right on this question. Why not see where you went right and utilize that technique on the same type of question. Make sure you got it right for the right reasons. Ask yourself, "why is the answer I chose correct and why are the incorrect answers choices incorrect?" Only by repeatedly asking yourself this question, will you start to see the underlying patterns of the LSAT.
Now, after you've analyzed your practice LSAT, what you should do is practice. Was your weakest section Logical Reasoning? Was your weakest Reading Comprehension passage the science passage? Was your weakest Logic Game an "In/Out" group game? Well gather up whatever section/question/passage that is and practice. Get to the heart of your weakness and vanquish it!
(3) Calm Down
There is a point where you will hit a wall in your studies. Some of you gunner LSAT prep students will work yourselves to the bone. You work so hard that at some point all the words on the page seem to fizzle together and nothing makes sense. Your practice LSAT score will naturally be lower because you were too tired, but then you get so worked up you study more and it's a disastrous cycle. Try not to take more than one practice LSAT a day. Really one is enough as long as you are analyzing and practicing accordingly each day. And remember, doing individual LSAT sections under time pressure, as opposed to entire LSAT Prep Tests, is a great way to study but avoid burning out.
Hope that was helpful! You're on the right track, but remember that studying a lot is not necessarily the same thing as studying well.