It doesn't necessarily have to be really, horribly, forgot-to-wear-a-bra-to-school humiliating to be fun. A few simple around-the-house ideas:

Let her declare Panty Days or Commando Days, when you are required to wear her panties (clean or dirty) or no panties at all. Take it a step further by wearing her garter belt and stockings.

Sit at her feet instead of next to her while you're watching TV.

Let her order for you in a restaurant.

Call her "ma'am" for a designated period of time, at home or in public. (In a non-sexual context).

Let her come up with some demeaning nickname for you, for use at home or in public.

Do housework in little or no clothing. Allow your "employer" to sit and sip iced tea and sexually harass you.

If you try enough stuff, you'll find something that genuinely pleases her and is also a turn-on for you. She'll learn how to push your buttons to make you feel more and more like the dirt beneath her feet. Enjoy!