My first attempt of CSS was in 2013 where I prepared for two weeks (it was a blind attempt) and mostly relied on existing knowledge and information gained via book reading and attending various informative sessions at Karachi Literature Festival. My DMC was as follows:

Candidate Name : WASIO ALI KHAN ABBASI
Roll No: 06238

COMPULSORY SUBJECTS

Essay 28 (Social Media topic)
English 59
General Knowledge 127
GK1 (Everyday Science) 34
GK2 (Current Affairs) 60
GK3 (Pakistan Affairs) 33
Islamiat 51

OPTIONAL SUBJECTS

Sociology 47
Journalism 55
British History 73
Paper A 37
Paper B 36
Psychology including Experimental psychology 74
Paper A 14
Paper B 60
Total Marks 486

Despite being first attempt and preparing without any guidance, I managed to pass most subjects and failed only in Essay (which was unbelievable since essay writing is one of my strengths). Nevertheless I decided to try my luck for 2014 exams.
I started working in a good company as Marketing Executive and had an understanding with my boss regarding 2014 exams. I changed my optional subjects since Sociology, Journalism and Psychology did not satisfy me. I chose Political Science, International Law and Constitutional Law in their places.
I took two months off and joined DHA Library in January this year. Prepared for just over two weeks by studying everyday from 10 am to 6 pm. I left for Saudia to perform Umrah with family and returned after 15 days, in the first week of February. In Saudia I did not get any time to prepare for the exams at all, and when I returned just handful of days remained to the start of CSS examinations.
Of those few days I spent three at Karachi Literature Festival which is held VERY close to CSS examinations. Following is my DMC:

Candidate Name : WASIO ALI KHAN ABBASI
Roll No: 09518

COMPULSORY SUBJECTS

Essay 45 (Great Nations topic)
English 43
GK1 (Everyday Science) 57
GK2 (Current Affairs) 38
GK3 (Pakistan Affairs) 52 (147)
Islamiat 52

OPTIONAL SUBJECTS

Political Science
Paper A 57
Paper B 56 (113)
British History
Paper A 42
Paper B 51 (93)
Constitutional LAW 18
International LAW 44
Total Marks 537

In both attempts I failed one subject and aggregate score was lower than 600.
What I have learned in these two attempts is that CSS in itself is not difficult. If you get one whole month to prepare undisturbed and study with peace of mind, you can prepare well. You need some smart thinking when attempting the exam so that you don’t mix the questions up or misinterpret them, resulting in low marks or outright rejection.
I have also learned that your answers should have strong opening, particularly Essay, where examiner’s attention is grabbed and he/she kept hooked till the end of your answer. There is no definite rule for that except the use of your knowledge combined with some strong writing to sell your answer to the reader. If you lack the ability to sell the answer in the opening lines, there is a good chance the marks awarded will be low.
I have exhausted both of my attempts and I’ll be 28 this month. I do not know if I would ever get chance to make my third attempt (2016 exam). If anyone needs my help in understanding CSS or require help in one of the subjects where I can offer anything, do not hesitate to contact me. I may not have managed to clear the examinations but at least I have some good experience to share and knowledge that I may be able to transfer.

Good luck to those who will appear for 2015 exams.