hi…
(i m sorry about the grammar and word mistakes )
I dont know exactly where did i get this idea, i think it came from one of my normal dream.
The great don juan teached carlos castaneda how to make a force object. 
,Teaching of Don Carlos, by Victor Sanchez, there are some instructions and theories how and what is ,power thing’’ When i get that idea first ,i was thrilled… i quess one of my dream guide helped with my problem, it wasnt really a problem… i thinked many times how is shared dreaming possible, i even tried to go my friends dream but it didnt work… i ended up some really different places.
If anyone have read castaneda’s books, don juan told carlos to make a ‘‘dreaming ring’’
1 ring will help its owner to get more lucid and more vivid dreams. It cant be any kind of ring, it must be special for you.
Making a force ring: have a ring, you should find its tiniest detail… and memory it’s speccialities. If you have memorised all features what your ring have, now you must find your own ring in a Lucid Dream, it must be the same as in the reality, and then it will be a ,dream ring’’ for you. U should bare it many times as possible when u sleep, if u don’t , the force will disappear. 
I had one ring… i turned it into ,force object’’ . it helped me getting many Ld’s.
But one day power of my ring was lost… and some days after, it disappeared.
(vanished)
Thank god i have brother who makes jewlery… now im waiting for my new ring.
Anyway my theory getting shared dream is:
Two fellows who have their power rings made… it sounds like a ,lord of the rings’ ’ They should swap their rings… by doing that, link or a connectian will be made between them.
That link works telepathly, now you and your mate should give themselvs a task in Lucid dream… ,Go to my rings barrier dream’’ ! (or something like that) 
close your dream eyes and really mean that task you gave… next moment you and your mate are some place that you both know… if u both give task then the ,uplink’’ is stronger, and ,the signal’’ will not be lost so easly.
Oke… i will try to find evidence that it really works, thanks anyway! 
Send me letters about shared dream theories ! bye
