I went to a coaching institute (name and city shall remain unknown) for 2 years. I used to study for 2 hours per day on my own and 2 hours per day in coaching. Nothing spectacular. Now that I think about it the biggest benefit of coaching was the quality of their teachers. If I had similar teachers in my school, there would be no need of coaching.
I gave JEE as well as AIEEE and UP state exam and I was ready to take up the best seat according to my performance. I don't think I had it in me to repeat and study for JEE again.
I don't really like coaching, especially today, where they are exploiting the students and their parents really with huge fees. In some states, they have some really poor model of coachings where they teach from 5 in the morning to 11 at night. Don't people go mad in such coachings? I don't know why the students want to go through such terrible conditions and the parents want it for their children.
I am a firm believer in putting "reasonable" effort to achieve something. If you cannot achieve your goal in that, it is not meant to be. Even if you get into IIT (or any other school/profession) after "unreasonably" high effort, it will be hard to maintain that position once you get it because you have to work very hard to maintain that status quo while it will be easy for your peers because it comes naturally to them.
Sorry for an unexpected answer. I am more of a "Go with the flow" kind of person rather than a huge "planner." So, I can't list down all the steps I took to prepare for JEE, because it was not really that planned.