In last two years, with notification coming in February, UPSC now roughly takes around 15 months resulting in a little squeeze in time-period for complete exam process.
To encounter emerging trends, it is prudent to adopt an integrated approach and should commence preparation with General Studies (Main Examination oriented).
Before you begin, self-analysis is must to identify your strengths and weaknesses. This will help you in understanding the examination related requirements and how much effort you need to put in. it will also help in recognizing areas which need more attention and accordingly prioritize your study-plan.
A strong desire to accomplish goal will motivate you to work hard and clarity about the examination process will help you in discover the right direction.
Commence your preparation with some basic books to lay a solid foundation before you advance with your study-plan. The following article will help you in making a better use of NCERT Books.
How to prepare with NCERT Books
Also, cultivate daily Newspaper reading habit and learn to make self-notes. It is must to build a long term awareness and knowledge relating to contemporary issues and developments as UPSC is focusing more on Currents.
How to read newspapers
How to prepare for current affairs
How to make self-notes from newspapers
As you plan to appear in CSE 2013, you should recognize a pair of suitable optional subjects which can lay a hand in your success. You should make a strategy that General Studies along with at least one optional subjects get prepared before the notification for CSE 2013 comes in February 2013.