The common denominator seems to be (very) open communication. It lays a solid foundation.
I look forward to more views as each answer has already started to 'unmuddy' the water for me slightly. I thank You for each response.

Please may I add another question? Would You as a Dominant do a scene with a brand new submissive? (Thus as a Top and not part of a relationship? I have previously met a Dominant and that is what he enjoys, meeting new subs and 'initiating' them into BDSM)

I look forward to learning more.