Time management is an old and often discussed problem. But in the era of technology, thankfully there are many free solutions available. A JEE aspirant has to keep a good control on how is he spending his time. One useful tool from google is a "cook timer".

   JEE aspirant may use this in the following ways:
   -- Say you have to revise 4 chapters in Physics. Put your timer in 20 min + continous mode. With each beep, religiously move to the next chapter. That you will not sink in one chapter but this timer would remind you that time is now to move on !