Oooohh, endless possibilities...*grins* Just a little brainstorming...
-picking underwear (or lack thereof *grins*) or a certain colour/type of clothing to wear
Excellent. I do this all the time and there are endless variations.
-control her masturbation/orgasms
Yep, both ways. No masterbation at all. Masterbation up to but not including orgasm. And my personal favorite... Masterbation to full orgasm. You set the times and/or placeses.
-have her wear a piece of jewelry just for you...or ask her to write something on her body...
Yep, Great as a constant reminder.
-how would she handle speech restriction? Being silent for a certain period of time or restricting/requiring the use of words you pick...
Interesting.....
-have her practice slave positions while thinking about you...(God, I love that, lol)
All the time baby!
-find out what's challenging for her and what's fun to do and then use it with mini tasks or daily routines for her.
Find out her fantasies and incorporate those into these minim tasks.