I am not sure if something like this or this has been thought of but this is what I did.
I've gone into a light trance by pencil tapping.
All you need is a sharp pencil and a hard surface... of course,hands. :-)
Ok this can be open eye or closed. I did it with open eyes and just looked somewhere.
What you do is start rapidly tapping your pencil and eliminate all other factors but hearing. Focus only on your ears and the sound of the tapping of the pencil. Keep doing that for a while and start to slow down your tapping when you feel that you have gone long enough then finally stop.
That's it.