Usually I use a multitude of techniques to stay awake. I typically start off by just counting backwards from 100 to zero. The best way to do this is to count down one after each exhale. However, after about counting down to 80 or 70, I find that my mind starts wandering and daydreaming. Whenever this happens, I do one of two things:

1) Reverse blinking. If you haven't heard of it, it's just opening your eyes for a half a second, then closing them for a few seconds (like blinking, but instead of closing your eyes every few seconds, open them). Just repeat that process until you feel focused again and then continue on counting backwards.

2) FILD. It was mentioned above, so I won't go into detail about that.


That's what I do to prevent falling asleep. Usually, I'm in SP way before I hit zero counting backwards. Just remember to focus wholly on the task at hand; be it counting backwards, reverse blinking, or FILD.