The process of long-term preparation is based on consistent perseverance and long-term commitment towards the goal of IAS.
Keeping the fire kindled across the time is a threat most cannot do with. I would in here suggest few methods to keep you on course for a 2 to 3 year-round preparation. I have no comments beyond that timeline.
1. Reading the syllabus mains every day.
2. reading Hindu and economic timed for one hour.
3. viewing Doordarshan news.
4. BBC news.
5. Rajya Sabha channel discussion.
6. Writing at least ten minutes on any topic you like.
7. Make a chart of articles from polity and try reading.
8. Start working with an atlas.
Do all these daily 4 hrs required, you will be a well-read person when hall ticket comes, and that's exactly UPSC asks for.
Best of luck