Hi HappySaban_RTR,
Thanks for your question. Unfortunately, there is no "magic bullet" for inference-making. The latter is a process that can only be perfected with a lot of practice. It is as much a function of proper diagramming techniques and the ability to see connections between the rules, as it is a matter of correctly analyzing numerical distributions, using Templates, or identifying significant points of restrictions on your base (which itself can result from the use of Not-Laws, among other deductions), etc. Sometimes, inference-making is a function of only one of the above-mentioned factors; more often than not, however, it is a function of all of them.
If you're struggling with some of the more advanced games, and have already taken a full-length course, I'd highly recommend our Advanced Linear Games course, which shows high-level inference making in action:
http://www.powerscore.com/lsat/advanced-logic-games/
It's a great way to continue your studies and take them to the next level, although I'd caution against waiting until September 2015 to take the LSAT. If you study efficiently, you'll run out of questions to do way before then, or - worse - forget some of the techniques you've learned in class. I would aim for June 2015.
Let us know if you have any more specific questions that we can answer.
Thanks!