I would take a practice test untimed. When I did so, it improved my confidence and timed score immensely. When you take them untimed, you have time to think about your decisions making it a great tool to sharpen those decisions.
Take an untimed test. You'll catch your mistakes and sharpen your decision making skills. I wrote about it on a discussion post a while ago. An untimed test gave me confidence in the timed tests I took after.
I just finished it tonight. Thought the RC and LR sections had some rough spots. Did worse than I expected in LR and better than expected in RC. Scored a couple of points higher than my average, as of late, so it was a nice confidence boost. :)
If you feel unprepared and not ready then you should consider taking it in October or December instead. The LSAT is an exam you need to be ready for and being confident plays a big part in it - and confidence comes with lots of practice and good results.