Create or find a three month LSAT study plan and stick to it!!!
In terms of the LSAT, I cannot stress the importance of practicing daily on your weaknesses. As with many standardized tests, many people, when given an unlimited amount of time, can score well. However, there is a time limit. Learning how to take the test is only half the battle. Taking the test well in the allotted time is the real struggle.
I would suggest using the PowerScore Bibles to learn tips and tricks and get practice approaching exam-like questions. However, it is imperative to through Official LSAT tests regularly, as they mimic the test you will eventually take. It is also important that you read through your answers and understand why you got them wrong. The Logic Games section is the one that is objective enough to be mastered with the most practice. The other sections will likely cause more frustration. Use these books to "learn" ways to approach the different sections of the test. Then apply that knowledge to the prep tests that you buy.
General consensus posits that testers should take three months to prepare for the LSAT. Do practice tests from the beginning, slowly plowing through them then reading the explanations for the answers. The closer you get to test day, the more tests you should take under regularly timed conditions.
This website provides a great study plan to follow if you are using the PowerScore materials. My biggest regret is that I did not follow it through and did not allow enough prep time. I think if I had strictly followed the schedule, I would have been happier with my score. I had gotten to the point where I could work through many of the questions and come to the right answer; I just couldn't do it within the allotted testing time. As with anything, practice makes decent, particularly in terms of working faster.