In my bed. As much as I enjoy pain, (spankings, nipple clamps, etc.) I want to be comfortable when receiving.
In the morning when I rise and before I go to sleep. I like reading erotic stories to bring me there, sometimes it will be a story or a video. Other times a scenario I create in my mind. A specific old bf, or a faceless man or couple, or my neighbor and wife who directs everything. She helps prepare the scene. Knowing how much the body can take, as a critical care nurse, encouraging him to spank me a little harder, pull my nipples, molest other body parts, etc. She pushes him to go further, yet not to harm me, not to cause damage.
Ninety-nine percent of the time I use a wonderful vibrator, the Lelo. But whether it is morning or night, my husband always asks do I need anything rubbed. He will manipulate my nipples while I use my Lelo.
When I am alone, and have a busy day ahead, I will use nipple clamps to achieve my goal. As one must get on with their day, I am able to reach my destination very quickly with nipple stimulation.