I finally discovered what works best for me.

i haven't been this cheerful, energetic and "alive" all the while.

completing work on time. having enough sleep. eating well and feeling good.

here are some of the habits which has helped me a lot:

- setting just 3 major tasks to do everyday (find your own optimal size for each task)

- read something or listen to something while you travel. (exceptions: don't do this standing, don't read on bus) I generally avoid newspaper because i hate people who spread their 'chicken wings'.

-avoid potato chips and junk food. eat sensibly.

-devise your own exercise routine. can't help you lose weight but prevents you from getting sluggish. my own routine takes about 10 minutes everyday, with a mixture of on-the-spot jogging, slow push ups, crunches, bridge, etc.

-have enough sleep.