IITians are successful because of their hard work, there determination and there positivity which makes them happy. Being a IItians its not a easy job for everyone, you have to work hard, concept should be clear and basic thing how you interpretate the things according to the situations.

See there is nothing written like you need the theoretical Knowledge, you should be engaged with the practical prospective also because sometime it helps you that is the key success for successful IITians. Another thing is that they keep motivated themselves, like there target is fixed mostly what I have seen that student focus shifts from here and they do another thing, so making a perfect or solid decision makes you Successful. 

Doing practice everytime, starting from the morning to the end of the day make a list what you have done which will increase you memory power for the exam point of view.

Believe in yourself, you should know your weak point and strong point, Listen no one is perfect everyone has some weak point but if you know you can solve. This is called strength which makes you Successful.

There is no special definition of successful. Success is in your hand, go ahead, do regular work but with lots of positive mindset. So I am sharing one of the best lines said by Respected APJ Abdul Kalam.

                                                         "Learning gives Creativity,

                                                         " Creativity leads to Thinking 

                                                         " Thinking leads to Knowledge

                                                      " And Knowledge makes you Great.

So if you think you can have the ability, power just break the resistance which stops you..