a few ideas that spring to mind:

- a few little stripes from Mr Cane across her bum -they dont need to be hard to leave a mark
- speculum (spelling?) either in her pussy or bum stretching it wide open
- nipple clamps with a hot load on her face

I liked the idea that someone said handcuffs, but why not go one step further and do some of that fancy japanese rope work around her boobs, tying her arms behind her.