To test her reactions and feedback on certain toys (the nice ones as well as the mean ones :) I strip my new submissive nacked onto the medical chair, blindfold her and make her listen to the thrilling sounds of "2chellos".
I can make her cramp and moan by hitting all the right spots so that she might enjoy this half an hour session and so that she stays always very close to the edge of cumming - of course without reaching that final orgasm :)