Position practice. A couple that allow meditation or self-contemplation. A couple that make her feel exposed. One for proper presentment at punishment, one for proper presentment for sexual use.

Whether you create them yourself, borrow from any of the various sites online, use the Gorean positions, or actually task her to create a set of them for your approval (in itself, a good task,) you will enjoy knowing she's increasing her stmina and strength (of mind and body) in your service... and you get to correct her posture whenever she's not doing them to your satisfdaction.