Power exchange is fundamentally important to me, I believe it's the basis of everything I do in BDSM. The emotional rush when someone kneels to me or speaks words of submission is quite as much of a pleasure as any of the physical manifestations. One of the most important moments in my relationship with thir was the first time that, outside of any role-play or sex and in the middle of an ordinary day, she spontaneously fell to her knees at my feet.
I've written elsewhere of a moment when I realised just how much power in itself meant to me. I was playing with a femsub from my local munch while thir was away, and I'd made clear in advance that we weren't going to have sex, but either she'd never accepted that or what I'd been doing was too arousing and she started begging me to fuck her. And I realised it was no effort to keep my word: having this naked collared slave grovelling at my feet, humiliating herself in the helpless grip of a need that I controlled, was as much of a sexual thrill as doing it. In fact, giving her what she sobbed for would be less satisfying than keeping her suffering in my power. I'd had a lovely time whipping and torturing her before, but it's that moment of total control that shines in my memory.
I've only played at submission a few times, in strictly role-play situations, but being under the right person's orders is a thrill that makes me breathless before they lay a hand on me. But it's very rare that I can give someone that kind of control, and so far it's always been my choice. I occasionally enjoy the fantasy of meeting someone who'd capture my will so that I just had to submit to them, but I don't think it's going to happen in this life.
Do ask more, always glad to help a fellow author get the feeling right.