We've been working on this in our project recently - and are trying to develop a layered system so our gesture can be used for multiple purposes. This is under active development, but there are a few examples of defined gestures. (Rereading this I want to make clear that we are a lab developing a project that uses leapmotion but we are not leap motion)
GitHub project branch (feature): https://github.com/maine-imre/handwaver/tree/feature/abstract-gestures
Folder within branch. https://github.com/maine-imre/handwaver/tree/feature/abstract-gestures/Assets/Scripts/gestures
GitHub issue: https://github.com/maine-imre/handwaver/issues/14
Feel free to comment on the issue if you have comments or questions for our team, we'd appreciate the feedback.