Tricks may not be necessary if you're really that sleepy. Just give in to your system's urge and you'll fall asleep immediately thereafter. You may want to drink hot milk or water. They calm your nerves and help you get back to sleep. In my case, I start work at 6 o'clock in the morning so it would be foolhardy for me to not wake up around 5:00 AM.
I have been waking up too early during my exams and when I have lots of work to do. I am sure that it helps me during the exams as it helps me to study really well. But it also makes me very tired. I am sure that the it is also a very good habit but the kind that I hate doing.
I would actually like to wake up earlier than I need. I wake up late, get ready in a hurry and always go to work late because I can never wake up when my alarm rings and keep on snoozing it... However, maybe a good idea to go back to sleep is to listen to some classic music or even turn on the TV and start watching one of those relaxing programs that are on cable sometimes early in the morning.
LOL isabbbela, it's case to say that we never have what we need! You do have a point there, when I wake up too early I start washing dishes or doing other tasks, but during the day and especially at the end of the day I resent from day because all my energy seems to be gone.