Go through few blogs of toppers,some of the well known websites, Go through the quora website and answer the questions. Read The Hindu newspaper daily to stay update with IAS. Few of the suggestions to follow are:
Start reading NCERT from class 6th to 10th, to some extent till class 12th. It will build up your base and yes, 2-3 direct Qs in Pre are from NCERT.
Make notes of whatever you are reading.
Read newspaper daily and try to analyse the news, recent tragedies to staty update with general knowledge
Go through the previous year Qs paper of Civil services.
Discipline and patience are key to success in civil services, to add up it will make you a great human being too
You can try to join Coaching institute for better understanding and knowledge. You can look for some of the good coaching institute like:
1. Chanakya IAS Academy
2. Rau’s IAS
3. Sriram’s IAS