Mix of both. I have yet to ever see an original idea. Despite what some may think our minds do not create something from nothing and the more unique it is the less understandable it becomes. For me, a lot of inspiration comes from photos and music. Literally, have hundreds of gigs of reference materials and it never seems to be enough. Books can be good as well. There are also some practical considerations as well as ideas created from bashing things together can be produced exponentially faster than trying to be completely original. Early on creating original ideas was a huge bottle neck for me, when you accept that nothing is original you can ironically, create better ideas faster.
