TIPS by Toppers
I believe that written part of CSS is not a test of knowledge of the candidates; Rather it is the test of their analytical skills. Most of the questions in the papers are of application level in which candidates are required to apply their knowledge. So in order to get good marks in written, the candidates need to improve their analytical and application skills by practising questions from the Past Papers after they have completed their preparation.
ASP Mufakhar Adeel 2nd Position, CSS-2006

English Essay is the only paper to evaluate writing skills of the candidate on any topic. Students must have good understanding and knowledge about societal issues like poverty, gender discrimination, social inequality, women empowerment; economic issues like tax reforms, budget, national finance commission award; religion like Islam and West, Islamophobia, Islam and terrorism, pluralism; scientific issues like global warming, pollution; national issues like democracy, military intervention, provincial autonomy , energy crisis, indepedence of judiciary, media; international issues like global terrorism, credit crunch, new world order.

-Syed Nadeem Abass 37 common, PSP

Two things play vital role: firstly, consultation of the original source helps you get the top position. Secondly, written tests, as many as you can, are very beneficial for getting highest marks. And I adopted the same strategy for topping written exam.

Abdullah Khuram NiaZi 2nd Position PMS Competitive examination 2009/10

I got 215 marks in interview and they are considered to be quite high. The main theme in interview is your confidence. In interview they are looking how well you communicate verbally. so you should speak good English with correct pronunciation. Next what matters are your regarding various national and international issues. You should have clear views which you should be able to support when called upon. One should not have extremist views- a moderate and balanced approach is preferable.
-Zeeshan Shafique Siddiqui 8th Postion, CSS 2007, PSP

A candidate must consider his/her own ability to understand and grasp all those subjects which he/she thinks appropriate for selection. The second consideration must be based on choosing those subjects which can fetch good marks.
Hussain Sarder Deputy Secretary (Finance) Government of the Punjab.