From under graduation stage you can start preparing for Civil Service Exam
Read Newspapers, Magazines, watch TV debates etc, for important national and international events.
Go through NCERT book for classes XI & XII for Arts subjects & classes IX & X for Science subjects.
Practice speed writing, legible writing and précis writing.
The preparation should ideally begin 8-10 month before the first Prelims.
The first 5-6 month focus should be to cover the Mains syllabus thereafter for preparation of Preliminary.
Before deciding on the choice of Optional, interest in a subject must be prime criteria influencing your choice.
It is essential to prepare few essay. Essays carry marks hence style, skill & speed writing is essential.
Consider other career options, before you finally decide upon Civil Services.
Work hard to come out with flying colours