I started studying for the December 2012 LSAT 2 months before it was administered with a Princeton Review study guide. I had always been good at standardized tests and figured I wouldn't need all that much prep to perform well and would even outperform my PTs on test day; 170+ seemed like it would be cake. The week before the test, I started to get a bit nervous about it: my highest PT had been a 163. Instead of making the smart decision to opt out and study more, I stubbornly went ahead with it so as to not disappoint my family/friends/girlfriend who knew I was supposed to take it that Saturday. Ended up with a 159.
After receiving my score, I immediately signed up for the June test; I knew from the get go that that score wouldn't be good enough for the schools I wanted to attend. Around March/April of 2013 I discovered TLS and its LSAT prep forum, and subsequently purchased the Bibles and Manhattan's LR guide. Though my prep felt more intense than the first time around, in retrospect it was still pretty half-assed. The two weeks leading up to the June 2013 LSAT I tried to cram by taking timed PTs every day, sometimes multiple times a day, and saw what felt like months of effort go to waste: I was only averaging a 166 (with a huge asterisk next to it) and was stressed and unbelievably frustrated. The day before the exam I was faced with the same decision I had to make several months before, but this time I chose to opt out and wait for the next administration of the LSAT.
The fallout wasn't pretty: my parents didn't understand why I would waste their money like that by cancelling my registration the day before the test, and they felt I was spoiled/ungrateful for their financial contributions to my education. I just had to grin and bear it while I began to implement my new study plan. After taking a week off, I purchased the Cambridge LR, LG, and RC books and started to grind out problem sets from each every single day. I would spend 5-6 hours a day just doing LSAT problem sets, including during my lunch break or during any down time I had at the internship I worked. After a month of that, I incorporated biweekly PTs into my regiment and would incessantly review the types of problems I got wrong by drilling them over and over again. By the end of the summer I was averaging just over a 170, with a few outlying scores of 175-177. Just over a year after I started studying for this damn test, and 11 months after my first bout with it, I saw this on my LSAC account's page:

My cycle's just getting started and I'm already in at three T-14s, an outcome that seemed unimaginable after I received my first LSAT score. As a URM, I want any other URMs who read this and are iffy about retaking to know that this test is conquerable, it just takes an incredible amount of time, effort, and motivation. This forum has the resources, for anyone who so chooses to utilize them, to help you achieve that coveted 17X score. Don't settle and hope your boost will be enough to propel you over the LSAT hurdle and into the T-14; retake.