vistana
First I hope you haven't bitten off more than you can chew. For me as a very experienced real world Dom for 35 years, it is that she trusts me enough to allow me to have her at my mercy. I expect to earn that trust as we go along and to continue to earn it on a daily basis. Understand the thrill it is to be alone with her and have her with a gag in her mouth so that she can;t scream for help, blindfolded so that she can't see what I am doing to her, ear plugs in so that she can't hear what I have or where I am, add to that I have her bound in such a way that she get free and sometimes even move much.
The level of trust she is showing at times like this is really unbelievable to me, I would never allow myself to be at someone mercy totally helpless. It is the same with the SM part of the life she is trusting me not to do real harm.
There of course is the ego builder of being called Master and sir in a very respectfull manner. I warn any lovely that I accept as slave that there will be a time that she will slip in public and call me Master. So far that has always proven true.
I could tell you what submissive tell me does it for them but I can't speak first hand. Ask them about how and what puts them into subspace may be a good start.
Russell