My girl and I don't have a really serious relationship -- we see each other once or twice a month, and we both see other people. We have two ongoing rules. One is that when we are having sex in real life or having cyber or phone sex, or if we are talking online or on the phone and she wishes to masturbate, she can't cum until she has my permission. The other is that at any time I can text or call her and ask for a picture of her or part of her in any position or clothing/lack thereof that I wish, and she has to send it to me immediately.
D. does not have many rules for me, either. The one thing that we always do is, when he gets home, I sit down at his feet and remove his shoes and socks for him. Usually I give him a quick foot rub, too. We've done other things on a limited-time basis, like me having to be naked whenever we're alone in the apartment, or having to wear certain undergarments, etc.