There are other forms beside rope. How about leather cuffs and chains a favorite of mine she gets to feel the coldness and hardness of chains on her body and realize she hasn't the the strength to tear them apart or the skill to undo a padlock. Then there is stocks both the fixed ones and the one that are really spreader bars with cuffs for ankles, wrists, etc.

I love the heavy fixed ones that also padlock down. Nothing is hotter then knowing she can't do anything to ease that pain in her legs, back, neck etc. except find subspace, while I enjoy that helpless body.

Then there is the wonderful gadgets and funiture that can be used.