It's the same thing in improvisation, m1469, it's impossible (without resorting to sheer randomness) to create something which is not in some way or form a recreation. Like a child, something unique, but rooted in the genetics of it's parents.
I have said before, ironically one of the things that improved one's improvisational skills most is working on repertoire(because all of the elements you improvise with are previously concieved elements).
Take a piece and mess with it, work from it's foundation and alter the harmnony, rhythm, melody, figuration - when you come up something good, repeat it and it will be remembered, and become part of your creative/recreative subconcious palette.