I'm looking for any existing touch gestures that mean "create new" (e.g. "create new document", "create new graph", "create new tweet", etc). Can anyone cite any existing "create new" gestures?
Gestures that don't mimic real physical interaction are not easily learned. I would suggest you do not use a gesture for this but a button, icon, or text instead.
Questions to ask before introducing a gesture:
Am I adding value? Or is it a gimmick?
Does this gesture make sense if it were manipulating the physical.
How many seconds does this add to the users goal? Both in action and in learning.
I believe a gesture would come with familiarity in using a product, much like keyboard short-cuts on OSX & Windows.
A button should be provided to create new, which can be hidden within an option screen, along with the ability to create the gesture for create new.