I had recently finished the "Art of Dreaming" and I took from it the technique of applying pressure to the roof of the mouth with the tip of the tongue. It took me an hour to fall asleep but I had waken up three times in an hour from over excitement of the lucid dream but got back into the the Lucid Dream through a WILD three times in a row. I think tongue technique works the same way the finger tapping techniuque works:

http://www.dreamviews.com/forum/viewtopic.php?t=5270

Personally, I think some of the stuff he wrote pertaining to his daily life has been questionable to myself, but the stuff he witnessed and has been to in dreaming, I have heard from several people that never heard of castaneda.