While this is a little outside my expertise have almost no submissive impulses myself. I can give you my best guess.
Act with confidence. Dress up especially if it makes you feel powerful. It is not about pain. It is about the thrill of Being out of control. You make him feel like your in control. Make him do whatever you want.
It hurts to beat people. You may look into something to hit him with unless your usually strong your hands well hurt quickly. .
It is ok to be a little selfish. Maybe sit on his face and slap his cock lightly unless he pleases you. Give him just enough to give him the thrill. You just have to experiment. But it has to work for both of you on some level. But really he is putting you in control.
Most of all TRY TRY TRY. Much better to try and fail. Then not to try