The first time I read Willam Buhlman's book, Adventures Beyond the Body: How to Experience Out-of-Body Travel, this "subtle realm" stuff was all absolutely new to me and I thought it was all theoretical or speculative.  I mean, he talks about being fully conscious and aware of being out of his physical body, of flying into space and changing forms, of seeing deceased relatives and having full conversations with them and with spirit guides.  

Since that reading, I have done several of the practices outlined in that book and have had 2 or 3 experiences of my own (related here and here).  

I am now re-reading this book and and it is helping me describe some of the things I've seen and experiences I've had.  It has a much more practical feel and is giving me even more ideas and inspiration.  It really can be done.  I have just barely scratched the surface of out of body exploration, but I know it's possible and am eager and ready to continue my explorations.  I have already begun putting the practices into place in my daily life, so I hope to have more to report soon.  A whole world of exploration awaits!