Cultivate a desperation in her. Plant seeds in whispers and midnight missives. Give her little tasks that propagate the cycles that will undo her. Have her touch herself, but never to climax. Rub your cock against her, but never penetrate. Tease and touch and play, but stop before she gets what she needs. Let the hunger grow and grow until all the other thoughts melt away.
Then sit her down on the ground, and give her one simple thing to focus on.