I've read this thread and found it very interesting. I'm extremely empathetic to the first poster's situation. Like you, I truly bombed the LSAT the first two times (yes two times) I wrote it. Scoring 152 and then 151.
Finally I hired an LSAT Tutor from PR. We would meet weekly. He made me ask myself soem hard questions that I feel would help anyone that is not scoring 170+ on their practice tests. Here's some advice:
1. Realistically, what score would the schools you're targetting want from you? Some schools don't average your past scores if you score 7-10 pts higher. But most take them all into consideration so project your average and see what you need to get into a school that is good for you.
2. Based on your practice tests, you should generally have an inclination to do better on some sections than others. Mine was games. No matter how hard I tried, those damn games killed me. My average before my tutor was 10-12 right out of 23-24 questions. After my tutor I raised that to 14-16. Still much less than I expected from myself. I suggest concentrating on the section that hurts you the most. Usually people say games are the section where you can improve the most (however that was not the case for me).
3. You're probably doing this already if you're following the suggestions in the prep book...but don't do the questions in sequential order. I hated turning back and forth, so if anything prioritize the 5 or so questions from each page. Really, really stick to this. Find the "type" of questions that give you the most problems and leave them to last.
4. This last point, to an already overly long e-mail, is how you "put it all together" for me anyways.
-Project the score you want.
-Realistically average out the number of questions you require to get correct in each section.
-Allot time so that you can thoroughly answer these questions. Example, if your goal is to get 18 questions right on the Games sections, than only do 3 games. Sounds crazy, but then you have those 35 minutes to do all 3 games and you should see your score improve. Then guess on the last game, and make sure you make that game the type of game that give you the most trouble. Do this procedure with every section.
IMHO, the reason why some people don't see significant improvement over their scores is because of time management. The books say it, but increasing your accuracy and then guessing on the rest is better than trying to give each question the proper attention it deserves.
My practice LSATs after this method say me scoring in the mid 160's and I cracked 170 once (wish that happened on the day of the test). I ended up scoring 158 on my third and final LSAT. I still blew the games section but it was a 7 point increase from my last one.
I guess that sort of hurts my credibility with this advice. But my LSAT Tutor was teaching several of his students this way, and he was accepted to Harvard and will be attending this Fall.
Good luck and if you need any clarification or pointers, please feel free to e-mail me.