excercise before you go to bed.
the more tired your body is, the more easy for the brain to switch it off.
also, get up early and walk.
have good meals, 6 light ones
follow the new food pyramid nutritional guide
keep clutter out of your living space, esp bed room
and pray before you go to sleep.
i am sorry if someone has disappointed you at work or at home or in a valued relationship, or you are up studying for an exam, then you have no option to stay awake.
best,
dushwari